For quite some time, my 4Runner has had an ever so slight rough idle.

Today, I jump in it and it runs like normal- head down the street to the gas station and top it off with about 6 gallons of 85 octane Shell, no biggie. About 15 minutes later it starts pulsing at low speeds uphill sort of like my transmission was slipping-I though OK that needs to be serviced maybe (it's been almost 30k miles). About a block later it runs like a total dog running really rich, misfires, and I get a flashing CEL (misfire, right?). So I get home and check all the plugs-they look clean. Clean the MAF again, clean the T-body again; start her up and no dice. I also checked for loose or cracked vacuum lines-nada.

Last night I did attempt to use some GUNK engine cleaner, but I was very carefull and sprayed it only where I wanted it. So I'm not sure that would cause any trouble.

So I'll get these codes pulled on monday. Seems like I've covered the basics. Anything else I should check?

 

Err..Seems like all of this was covered in Midiwall's thread. I have no idea how to check the coils so I'll leave that to somebody more experienced. Any other little things I can check?

 

Without the actual code, you might as well chuck a dart at a dart board. Could be a number of things. My first 3 thoughts are coil pack, 02 sensor, FPR

shots in the dark though...keep us posted.

 

How About . . . Bad Gas?

 

If you read about seafoam it gets crap all over your plugs after using it. I have a feeling its that. Just check em or change em again, its only 10 bucks or so.

 

Ok i didnt read the whole thing, sorry!

 

Hey Gapguy, My truck was running the same way. At a stop it would pulse like it was misfiring and when i tried to goto WOT it felt so slow! :pat:

When i got the code read from autozone it was a p1135. THis code represented and A/F Sensor Heat Circuit Malfunction.

I took it to the dealership early this morning since Im still covered under warranty. Ill be sure to tell you what they find.

 

Thanks everybody...I did check the plugs and they were all reasonably clean for the milegae thats on them, no big issues there. This morning (2 days later) I go to fire it up and guess what?!? Thats right, NO MISFIRE!!! I'm 95% positive I have a bad wire and it got wet. Nobody in town has a code reader for OBDII, so I drove to Lander WY (Fremont Toyota GMC) and picked up new plugs ($3.44 each, mighty rip off) and a set of wires ($58.64). By the time I was ready to head to service to get the code read, the light had gone out. They pulled the codes and I forgot the numbers, but it was Misfire on multiple cylinders, Misfire on Cylinder 3, and Bank 1 too lean. Popped in the wires and plugs and everything is still A-OK, actually a lot better than it used to be. Mission Accomplished, always the simple stuff!

 

(sung to the tune of the 12 days of Christmas)

"and a plumbing end-cap in your air hose..."

 

Best part about going to the Yota/GMC dealer is that I saw not one, but TWO GMC's being TOWED in with ROPE by Yotas!!!

 

blink - whatever happened w/ the dealer?

 

Huh???

 

well, after about 4k worth of warranty work and parts.... my trucks CEL is still on wit the same code, that my air/fuel sensor is bad (the replaced it 3 times) :pat: . They told me that there is nothing left taht they can think of 2 do . My truck has been stuck in open loop for about 3 weeks now and the exhaust tip is getting pretty black from running so rich. Ill start taking off my mods one by one to isolate the problem.... Ill report back then... has anyone else other then tacoma2x4 gotten this p1135 code?

 

it goes w/o saying that i am getting that code too, but i have an '01 4runner.

 

broknlgs24, how many miles do you have on the truck?

 

i'm guesstimating 50k.
i recently cleaned the MAF Sensor and cleaned/re-oiled the air filter. then took it to AutoZone and had them reset the code. not long after, the CEL came back on. i've yet to head to the dealer, but i assume that that's my next step.

 

The oiled filter may be leaving residue on the MAF triggering a faulty reading and a CEL. Clean the MAF, then drop in a paper filter and see if the CEL comes back after you disconnect the negative pole of the battery for 30 minutes.

 

bamachem - would this work? what if i were to disconnect the battery, remove the air filter all together and try. or do i need an air filter?

i mean, i know i need an air filter, but i'm only talking about for this test.

also, just disconnecting the battery will reset the CEL? if that's so, it saves me a trip to AutoZone.

Below is a link to another post documenting my issue. It's pretty much the same as what's in this post.

VSC OFF/VSC TRAC

 

if i am not mistaken, he is recieving a p1135 code like i was? which is a malfunction in the heater ciruit of the air/fuel sensor.

 

yes, i am definitely getting the P1135 code.