BAD hesitation/ power loss/ gas mileage - no check engine light/codes
01-09-2009, 07:32 PM
#1
Registered User
Thread Starter
Join Date: Jan 2009
Location: maryland
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
BAD hesitation/ power loss/ gas mileage - no check engine light/codes
PLEASE HELP! I have searched this forum and "Google" for many days and hours trying to figure out what is wrong with my 2001 4runner limited- automatic. I am going to be specific about the issue in hopes of really narrowing down the problem.
It began as just a very minor issue- a few times it seemed to "miss" upon acceleration after being stopped at a light. I took it to my mechanic (who has been very reliable for years)... he ran the codes and told me it came back fine.
Within two weeks, I was having noticeable trouble when accelerating from a stopped or slow position. Hesitation and "over-revving"... I had to very slowly pump the gas peddle (over and over) to pick up speed. Flooring the peddle only resulted in loud revving. Once I got up to speed, it would maintain okay, but I could not pick up speed fast enough to merge into traffic. Also, I could not drive up an incline without losing at least 20 miles per hour. My gas mileage became beyond HORRIBLE.
I cleaned the MAF (at the suggestion of this forum)... it did not help. I took the vehicle to a local "chain" for diagnostic... they could not figure out the problem. (I asked them about every suggestion I read about on this site)... They said- not fuel filter, O2 sensor, spark plugs, or transmission. They thought it was the MAF, and cleaned it again, but there was no change. After 3 1/2 hours, they gave up and didn't charge me for diagnostic.
Now (1 week later) it is not drivable. I can't go over 30mph.
Do I have an EGR valve (I don't think I do)? Where is the PCV? Could this be the fuel pump or the FPR? The mechanic said he checked everything, including a leak in the intake and hoses. Was something misdiagnosed or missed all together? Should I REPLACE the MAF first?
A few other things that may or may not be important-
I recently had front break pads replaced.
It seemed like having my ipod hooked up to the tape convertor made the problem worse (but I was told this was my imagination.)
It is not in 4WD and I don't have the emergency brake engaged.
THANK YOU A MILLION FOR ANY HELP!
It began as just a very minor issue- a few times it seemed to "miss" upon acceleration after being stopped at a light. I took it to my mechanic (who has been very reliable for years)... he ran the codes and told me it came back fine.
Within two weeks, I was having noticeable trouble when accelerating from a stopped or slow position. Hesitation and "over-revving"... I had to very slowly pump the gas peddle (over and over) to pick up speed. Flooring the peddle only resulted in loud revving. Once I got up to speed, it would maintain okay, but I could not pick up speed fast enough to merge into traffic. Also, I could not drive up an incline without losing at least 20 miles per hour. My gas mileage became beyond HORRIBLE.
I cleaned the MAF (at the suggestion of this forum)... it did not help. I took the vehicle to a local "chain" for diagnostic... they could not figure out the problem. (I asked them about every suggestion I read about on this site)... They said- not fuel filter, O2 sensor, spark plugs, or transmission. They thought it was the MAF, and cleaned it again, but there was no change. After 3 1/2 hours, they gave up and didn't charge me for diagnostic.
Now (1 week later) it is not drivable. I can't go over 30mph.
Do I have an EGR valve (I don't think I do)? Where is the PCV? Could this be the fuel pump or the FPR? The mechanic said he checked everything, including a leak in the intake and hoses. Was something misdiagnosed or missed all together? Should I REPLACE the MAF first?
A few other things that may or may not be important-
I recently had front break pads replaced.
It seemed like having my ipod hooked up to the tape convertor made the problem worse (but I was told this was my imagination.)
It is not in 4WD and I don't have the emergency brake engaged.
THANK YOU A MILLION FOR ANY HELP!
Last edited by lola; 01-09-2009 at 07:44 PM.
01-09-2009, 08:01 PM
#3
Have you tried a tune-up yet? May help. You should find a shop with a scanner and have it hooked up while driving to see how much fuel and air being taken and consumed. Your Mass air flow sensor sounds like the problem. Maybe price one you may just have to invest in it. It might have gotten beat wrong or jarded or shorted out by bad luck...
01-09-2009, 08:33 PM
#5
Registered User
Thread Starter
Join Date: Jan 2009
Location: maryland
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Believe it or not, according to most of what I've read on this website (and both mechanics), the transmission doesn't seem to be the problem. I really thought that was the issue initially... but most are saying it's unlikely. I will check the transmission fluid in the morning though.
I was told my spark plugs, etc. are definitely okay, but I think I am going to start with a tune up anyway. It can't hurt.
Then I think I am going to go with replacing the MAF or O2 sensor next, depending on everyone's suggestions.
Thanks for the responses!
Forgot to say- 130,000 miles on vehicle.
I was told my spark plugs, etc. are definitely okay, but I think I am going to start with a tune up anyway. It can't hurt.
Then I think I am going to go with replacing the MAF or O2 sensor next, depending on everyone's suggestions.
Thanks for the responses!
Forgot to say- 130,000 miles on vehicle.
Trending Topics
01-15-2009, 07:17 PM
#8
Registered User
Join Date: Nov 2008
Location: Vancouver< WA
Posts: 247
Likes: 0
Received 0 Likes
on
0 Posts
I had a very similar problem in my chevy blazer recently, and I was bummed since now I have a 4runner I'm going to be selling it. Anyway, the gas tank was nearly empty so I picked up some fuel system cleaner and poured that in then filled up the tank and within 5 or 10 miles she was running great.
01-15-2009, 07:23 PM
#9
It may need a tune up man how long you owned thr truck? It might now have had tune-up for years or even since 2001 lol. its possible. Does it idle bad when this problem starts? If so get out the truck and pop the hood and beat on the Mass air flow and see if ti stops. If so you need a mass air flow if not you may still need mass air flow but i could be something else. i would take it to a shop with a scanner and still have it drove with the scanner on it and pull codes. not all codes are always displayed through engine light.
02-02-2009, 11:57 AM
#10
Registered User
Join Date: Sep 2008
Location: new baltimore ny
Posts: 184
Likes: 0
Received 0 Likes
on
0 Posts
YOu might want to check to make sure that your exhaust is not plugged somewhere, at the cat or further back. A vaccuum guage from a local parts store is a real quick and acurate test for symtoms that your having. Most come with very simple directions
02-02-2009, 12:35 PM
#11
Registered User
Join Date: Sep 2008
Location: middle of no where Alaska
Posts: 4,355
Likes: 0
Received 2 Likes
on
2 Posts
Man, I would not suggest replacing the MAF first. Those things are expensive!! New, they are like $600+, but if worse comes to worse, get a used one through Nix99 in Washington. DeathCougar on this forum works there and I'm sure could help out, at least give you the number to call 
new brake bads are probably not part of the problem, especially since it got worse. They could be stuck engaged, but I'm sure you would be hearing a god awful noise from the front if they were engaged the whole time. Couldn't hurt to at least check to make there they aren't stuck engaged.
You say the iPod seemed to make it worse? Maybe the alternator isnt producing enough power to keep the battery charged all the way, therefore not allowing enough current to reach spark plugs, sensors and such. get that tested, as well as all the wires involved in the running of the engine.
Good luck.
new brake bads are probably not part of the problem, especially since it got worse. They could be stuck engaged, but I'm sure you would be hearing a god awful noise from the front if they were engaged the whole time. Couldn't hurt to at least check to make there they aren't stuck engaged.
You say the iPod seemed to make it worse? Maybe the alternator isnt producing enough power to keep the battery charged all the way, therefore not allowing enough current to reach spark plugs, sensors and such. get that tested, as well as all the wires involved in the running of the engine.
Good luck.
02-13-2009, 05:15 PM
#12
Registered User
Join Date: Jan 2009
Location: Caracas Venezuela
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
hello everyone, I have the same problem with my 93 4runner.
over-revving and had to pump the gas peddle to pick up speed, just 2 or 3 pumps or pull it all the way to make it run, but to me the problem became when i get stuck on a river, dead engine... have it change for a new one, change oils, the computer say no codes and have a fine tune up, there is not bad noises.
the 4runner past almost a month after the car have the new engine, have the water can be making some roll in this with u to lola?
over-revving and had to pump the gas peddle to pick up speed, just 2 or 3 pumps or pull it all the way to make it run, but to me the problem became when i get stuck on a river, dead engine... have it change for a new one, change oils, the computer say no codes and have a fine tune up, there is not bad noises.
the 4runner past almost a month after the car have the new engine, have the water can be making some roll in this with u to lola?
03-14-2009, 01:27 PM
#13
Registered User
Thread Starter
Join Date: Jan 2009
Location: maryland
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
I don't know if anyone will read this since it has been so long but I wanted to post an update just in case...
The dealer told me I needed a whole new exhaust---catalytic convertor, muffler, etc.
This is very disappointing considering it was already replaced in 05-- just above the 80,000 mile warranty! It had about 80,200 miles on it and the dealer would not even consider honoring it. Took it to a shop which repaired with aftermarket stuff (and refused to give old stuff back!).
I have read that it shouldn't have needed a cata. then, much less need another one but it does! (They were burned out completely.)
Also, the dealer failed to tell me when they called with the estimate that my rear "bell lock brake???" was stuck/engaged.
Needless to say, I could not afford the $4,100 repair cost. A friend disengaged the brake problem and said he "fixed" the cata problem.
Everything was fine for a while. Now, I have jerking, bucking at btwn 50-65 miles per hour. When I release the gas to slow down a bit, and then start to reapply slight pressure to the gas pedal, the car jerks. If I "floor it", the jerking stops. This does not happen at any other speeds. Recently CEL came on permanently after just blinking and then going off occasionally.
IF ANYONE HAS A SUGGESTION- PLEASE OFFER!
The dealer told me I needed a whole new exhaust---catalytic convertor, muffler, etc.
This is very disappointing considering it was already replaced in 05-- just above the 80,000 mile warranty! It had about 80,200 miles on it and the dealer would not even consider honoring it. Took it to a shop which repaired with aftermarket stuff (and refused to give old stuff back!).
I have read that it shouldn't have needed a cata. then, much less need another one but it does! (They were burned out completely.)
Also, the dealer failed to tell me when they called with the estimate that my rear "bell lock brake???" was stuck/engaged.
Needless to say, I could not afford the $4,100 repair cost. A friend disengaged the brake problem and said he "fixed" the cata problem.
Everything was fine for a while. Now, I have jerking, bucking at btwn 50-65 miles per hour. When I release the gas to slow down a bit, and then start to reapply slight pressure to the gas pedal, the car jerks. If I "floor it", the jerking stops. This does not happen at any other speeds. Recently CEL came on permanently after just blinking and then going off occasionally.
IF ANYONE HAS A SUGGESTION- PLEASE OFFER!
Last edited by lola; 03-14-2009 at 01:29 PM.
03-15-2009, 08:21 AM
#15
Registered User
Join Date: Jun 2008
Location: Columbia MD
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
You need to check you MAF, again its still common to your problem. I hate to say it but take it to a "good" Toyota Dealer. I have used the Toyota - Car Max in Laurel and had them diagnose a similar problem. They took into account all the checks I did and didn't try any "stealership" tricks. I listed the checks and parts I changed in trying to isolate the problem. They solved my problem replacing the MAF ~$800. (parts + labor)
03-31-2011, 07:12 AM
#17
Registered User
Join Date: Mar 2011
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Ok had this problem
I don't know if anyone will read this since it has been so long but I wanted to post an update just in case...
The dealer told me I needed a whole new exhaust---catalytic convertor, muffler, etc.
This is very disappointing considering it was already replaced in 05-- just above the 80,000 mile warranty! It had about 80,200 miles on it and the dealer would not even consider honoring it. Took it to a shop which repaired with aftermarket stuff (and refused to give old stuff back!).
I have read that it shouldn't have needed a cata. then, much less need another one but it does! (They were burned out completely.)
Also, the dealer failed to tell me when they called with the estimate that my rear "bell lock brake???" was stuck/engaged.
Needless to say, I could not afford the $4,100 repair cost. A friend disengaged the brake problem and said he "fixed" the cata problem.
Everything was fine for a while. Now, I have jerking, bucking at btwn 50-65 miles per hour. When I release the gas to slow down a bit, and then start to reapply slight pressure to the gas pedal, the car jerks. If I "floor it", the jerking stops. This does not happen at any other speeds. Recently CEL came on permanently after just blinking and then going off occasionally.
IF ANYONE HAS A SUGGESTION- PLEASE OFFER!
The dealer told me I needed a whole new exhaust---catalytic convertor, muffler, etc.
This is very disappointing considering it was already replaced in 05-- just above the 80,000 mile warranty! It had about 80,200 miles on it and the dealer would not even consider honoring it. Took it to a shop which repaired with aftermarket stuff (and refused to give old stuff back!).
I have read that it shouldn't have needed a cata. then, much less need another one but it does! (They were burned out completely.)
Also, the dealer failed to tell me when they called with the estimate that my rear "bell lock brake???" was stuck/engaged.
Needless to say, I could not afford the $4,100 repair cost. A friend disengaged the brake problem and said he "fixed" the cata problem.
Everything was fine for a while. Now, I have jerking, bucking at btwn 50-65 miles per hour. When I release the gas to slow down a bit, and then start to reapply slight pressure to the gas pedal, the car jerks. If I "floor it", the jerking stops. This does not happen at any other speeds. Recently CEL came on permanently after just blinking and then going off occasionally.
IF ANYONE HAS A SUGGESTION- PLEASE OFFER!
03-31-2011, 10:35 AM
#18
Registered User
Ok The CEL came on and may read a code for the EVAP system. When you put the vehicle in cruise it may do what my vehicle did. It stayed at speed but it gave short 1-3 second long bursts of acceleration. I had the same problem and had to get a new Fuel Tank Pressure Sensor. I have a 2000 suzuki grand vitara. After installing this part and driving for a lil while my CEL went off.
08-11-2011, 06:46 AM
#19
Registered User
Join Date: Aug 2011
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Same problem but still happening after lots of work!
2002 4Runner SR5 Sport Edition 161,000k miles – and I love my 4Runner! Had it for 5 years with no problem and I have the regularly scheduled maintenance performed. This is kind of long and for that I am sorry but I have done all I know to do here… 
8 months ago CEL's P1135 & P0420 came on. Changed out Air-Fuel Ratio sensor & cleared codes and all went well for about 2 months.
6 months ago P0420 came back but wasn't constant (meaning I'd 4WD up a mountain & CEL would go off for 2 weeks; hwy drive & CEL back on; jump a curb & CEL off for 1 week; hwy drive & CEL back on).
4 months ago local reputable mechanic ran smoke test & found nothing wrong so I drove on and ate up lots of gas while I saved money because I read in these forums its needing new cat-co.
3 months ago same guy runs another smoke test, changes fuel filter & resets system. I get SeaFoam from store & run 1/3 thru vacuum line & put rest in tank. Lotsa white smoke from that! Ran great but 3 days later CEL P0420 back on.
Took to local Toyota dealer for full $diagnostic$ and they say not cat-co but I over-oiled KN filter and screwed up Mass Air Flow Sensor so they change it out & put in Toyota air filter and I gave away my KN!
7/30/11 Driving home from trip 5 hours away and lose power on interstate… Going 70mph and all of a sudden I can only get 50mph and speedometer declining rapidly. (Like something's pulling me BACKWARD so harsh a loss.) Pressing pedal to floor does nothing but I let up for 10 seconds and depress pedal again and go awhile longer and lose power again. CEL comes back on & I get to out of town Toyota dealer who reads P0420 with hand-held. He says it's NOT cat-co but bad fuel, resets code and I go home (5 hour trip took 8).
8/1/11 I take back to local dealer and they cannot figure out any problems because they cannot recreate and there's no code to tell them what to fix. I leave told to keep driving and bring it back if CEL comes back on.
8/2/11 Clear out bad fuel, change fuel filter again and run 2 tanks high test. Runs well and no problems.
Until today.
8/11/11 Back to lack of power on acceleration from stop. Back to noticeable hesitation/skipping while driving on highway. Haven't had the full-on slowdown yet but I guess that's coming at some point.
I'm not sure where to go next or what to do. I do know that I was a danger to myself and the other people around me on I-85 while I was losing power, and I drive 80 miles on highway daily, so I'm looking for whatever help anyone can give!
Thank you!
8 months ago CEL's P1135 & P0420 came on. Changed out Air-Fuel Ratio sensor & cleared codes and all went well for about 2 months.
6 months ago P0420 came back but wasn't constant (meaning I'd 4WD up a mountain & CEL would go off for 2 weeks; hwy drive & CEL back on; jump a curb & CEL off for 1 week; hwy drive & CEL back on).
4 months ago local reputable mechanic ran smoke test & found nothing wrong so I drove on and ate up lots of gas while I saved money because I read in these forums its needing new cat-co.
3 months ago same guy runs another smoke test, changes fuel filter & resets system. I get SeaFoam from store & run 1/3 thru vacuum line & put rest in tank. Lotsa white smoke from that! Ran great but 3 days later CEL P0420 back on.
Took to local Toyota dealer for full $diagnostic$ and they say not cat-co but I over-oiled KN filter and screwed up Mass Air Flow Sensor so they change it out & put in Toyota air filter and I gave away my KN!
7/30/11 Driving home from trip 5 hours away and lose power on interstate… Going 70mph and all of a sudden I can only get 50mph and speedometer declining rapidly. (Like something's pulling me BACKWARD so harsh a loss.) Pressing pedal to floor does nothing but I let up for 10 seconds and depress pedal again and go awhile longer and lose power again. CEL comes back on & I get to out of town Toyota dealer who reads P0420 with hand-held. He says it's NOT cat-co but bad fuel, resets code and I go home (5 hour trip took 8).
8/1/11 I take back to local dealer and they cannot figure out any problems because they cannot recreate and there's no code to tell them what to fix. I leave told to keep driving and bring it back if CEL comes back on.
8/2/11 Clear out bad fuel, change fuel filter again and run 2 tanks high test. Runs well and no problems.
Until today.
8/11/11 Back to lack of power on acceleration from stop. Back to noticeable hesitation/skipping while driving on highway. Haven't had the full-on slowdown yet but I guess that's coming at some point.
I'm not sure where to go next or what to do. I do know that I was a danger to myself and the other people around me on I-85 while I was losing power, and I drive 80 miles on highway daily, so I'm looking for whatever help anyone can give!
Thank you!
08-11-2011, 07:00 AM
#20
Contributing Member
Join Date: Jul 2003
Location: Orlando, FL
Posts: 9,076
Likes: 0
Received 0 Likes
on
0 Posts
First of all, welcome to YotaTech and thanks for searching!
I had a similar problem to this on my '99 4Runner and it ended up being old plugs and a bad cat.
I would go ahead and replace the cat with a cheap one off of eBay. IIRC, the one I got was a Car Sound High Flow Cat but I could be mistaken...that was years ago.
Good luck!
Fink
I had a similar problem to this on my '99 4Runner and it ended up being old plugs and a bad cat.
I would go ahead and replace the cat with a cheap one off of eBay. IIRC, the one I got was a Car Sound High Flow Cat but I could be mistaken...that was years ago.
Good luck!
Fink
