After routine maintenance....P0125 & P0171
08-06-2010, 07:16 PM
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After routine maintenance....P0125 & P0171
Hey folks!
Today I did some routine maintenance on my 2000 4runner:
Changed plugs using OEM Denso's
Changed fuel filter using OEM filter
Drained Radiator, flushed with a garden hose, filled with yota red stuff and burped. (1 gallon of red stuff filled the radiator. After the first and second burp, it hardly went down, I only had to add a 1/4 gallon of water, then I filled the overflow to the top mark)
Everything went smooth until the two hour ride back to Philly from the Poconos. After about 20 minutes of driving, I got a P0125 (coolant temp too low for closed loop operation).
I pull over, turned car off, checked rad hoses - upper hose was hot and rock hard, lower hose was soft and not even warm. I opened the radiator and burped the system again, got a few more bubbles. I cleared the code and got back on the road.
20 minutes later...I get P0125 again, and P0171 (fuel trim - bank 1 - system too lean). I pull over and shut down. Upper rad hose a little softer than before and hot, lower hose is still cool and soft. Jacked up front end about 8", burped system again, cleared code, back to driving.
A few minutes later I get the same 2 codes again, but continued home. Car ran perfect, but it was sucking down a lot more fuel than usual. Once I got home, I checked hoses - upper one is hot and feeling normal (not rock hard), lower hose is again soft and not even warm. Burped the system another 2 times and still getting the same codes and the cool lower rad hose. Also, nothing got sucked from the overflow.
A little related info: A few months ago I had a bad A/F sensor (front sensor). I put in a new one from toyota, it's been good for over 1,000 miles now. So...not sure why i'm getting P0171.
Any ideas gentleman? The car was running perfect before I did all the work. I was trying to get the car ready for a trip to North Carolina, and figured I should take care of some maintenance I've been putting off, and now this! I know the usual issues with these codes (map sensor, a/f sensor, vac leak), but it's odd that they popped up after this maintenance.
Today I did some routine maintenance on my 2000 4runner:
Changed plugs using OEM Denso's
Changed fuel filter using OEM filter
Drained Radiator, flushed with a garden hose, filled with yota red stuff and burped. (1 gallon of red stuff filled the radiator. After the first and second burp, it hardly went down, I only had to add a 1/4 gallon of water, then I filled the overflow to the top mark)
Everything went smooth until the two hour ride back to Philly from the Poconos. After about 20 minutes of driving, I got a P0125 (coolant temp too low for closed loop operation).
I pull over, turned car off, checked rad hoses - upper hose was hot and rock hard, lower hose was soft and not even warm. I opened the radiator and burped the system again, got a few more bubbles. I cleared the code and got back on the road.
20 minutes later...I get P0125 again, and P0171 (fuel trim - bank 1 - system too lean). I pull over and shut down. Upper rad hose a little softer than before and hot, lower hose is still cool and soft. Jacked up front end about 8", burped system again, cleared code, back to driving.
A few minutes later I get the same 2 codes again, but continued home. Car ran perfect, but it was sucking down a lot more fuel than usual. Once I got home, I checked hoses - upper one is hot and feeling normal (not rock hard), lower hose is again soft and not even warm. Burped the system another 2 times and still getting the same codes and the cool lower rad hose. Also, nothing got sucked from the overflow.
A little related info: A few months ago I had a bad A/F sensor (front sensor). I put in a new one from toyota, it's been good for over 1,000 miles now. So...not sure why i'm getting P0171.
Any ideas gentleman? The car was running perfect before I did all the work. I was trying to get the car ready for a trip to North Carolina, and figured I should take care of some maintenance I've been putting off, and now this! I know the usual issues with these codes (map sensor, a/f sensor, vac leak), but it's odd that they popped up after this maintenance.
Last edited by stibz; 08-07-2010 at 05:39 AM.
08-07-2010, 08:10 AM
#3
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You seem to be doing the right things. I'd recheck the fuel filter for leaks--that might contribute to a P0171 and it's hard to get that installed right the first time. Eventually check or replace thermostat. Vac hoses not replaced are prime suspect since you changed plugs as it seems you know. Good luck..keep posting. The lack of answers does not mean there is no one reading. I love troubleshooting more than say....taillights.
08-07-2010, 08:24 AM
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Yea troubleshooting is fun, but I hate when it's my car 
... As for the fuel filter, when I first installed the new filter, I had a leak on the out-side of the filter, I tightened it down and it stopped leaking. I keep thinking about that damn filter...but it's not leaking?
So today I pulled the plug wires and added some dielectric grease just to be safe. Also cleaned the MAF.
Cleared the codes, went for a ride, pulled the same p0171, and p0125. Cleared them again, kept driving, then I pulled a p0141, heater circuit malfunction for the rear o2 sensor. I pulled up a screen and watched the voltage on both sensors, they both look normal.
I'm wondering if a faulty plug wire can cause this? I had a tough time trying to pull the drivers side plug wire closest to the firewall, I was pulling on it pretty hard, maybe caused a little damage.
She's still sucking down fuel, and the only other noticeable driveability issue is a slight engine pulsing every few seconds; almost like a rough idle, but it only does it for a split second.
... As for the fuel filter, when I first installed the new filter, I had a leak on the out-side of the filter, I tightened it down and it stopped leaking. I keep thinking about that damn filter...but it's not leaking?So today I pulled the plug wires and added some dielectric grease just to be safe. Also cleaned the MAF.
Cleared the codes, went for a ride, pulled the same p0171, and p0125. Cleared them again, kept driving, then I pulled a p0141, heater circuit malfunction for the rear o2 sensor. I pulled up a screen and watched the voltage on both sensors, they both look normal.
I'm wondering if a faulty plug wire can cause this? I had a tough time trying to pull the drivers side plug wire closest to the firewall, I was pulling on it pretty hard, maybe caused a little damage.
She's still sucking down fuel, and the only other noticeable driveability issue is a slight engine pulsing every few seconds; almost like a rough idle, but it only does it for a split second.
08-07-2010, 12:44 PM
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SO...I picked up some plug wires. As I'm installing them I noticed a dangling ground strap for the diagnostic socket next to the intake...the one I removed when installing the plugs!!!!!
It now makes sense why I was getting all kinds of DTC's. I hooked it back up, and after 30 minutes of driving and 3 on/off cycles, no CEL. The slight pulsing is gone, she's smooth as butter
LESSON LEARNED! lol
It now makes sense why I was getting all kinds of DTC's. I hooked it back up, and after 30 minutes of driving and 3 on/off cycles, no CEL. The slight pulsing is gone, she's smooth as butter
LESSON LEARNED! lol
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