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Discussion Starter · #1 · (Edited)
Alright, my check engine light came on a bit ago, and since it coincided with me hitting 101k miles, I thought it was just a general mileage-type light. So I ignored it for awhile since the car was running fine and (excuses here and) yeah, but then I read on here that autozone will check your codes for you, so I went and did that. These are the error codes I got:

P1138 - Lack of HO2S12 switch - sensor indicates rich

P1136 - Fan control circuit malfunction

P0455 - The PCM has determined that a large leak exists in the evaporative emission control system.

P0441 - The PCM has determined that the purge flow in the eaporative emission control system is incorrect for the current engine operating conditions.

It was raining at the time (if that means anything) and a couple things I should disclose since they MAY be relevant. I use 89 octane gas (is that bad?) and every time I fill up, whether it's on a relatively empty tank or a quarter of a tank, the car runs really really poorly for 1-3 minutes (like turns over for 10 seconds before it'll start, then runs well at RPM's above 2k, but dies at idle). Also, when I got my oil changed for the first time in this car (I've not had it very long and don't drive it very much - like 400 miles/mo) I didn't know I should use synthetic and so there's regular 10W-30 in it. I got a can of sea foam and I'm going to pour that in and when I finish a tank of gas I'll change the oil to real stuff.

Anyway, if anyone could give me some guidance on the error codes, that'd be great. Thanks!

justin

Edit- Oh, I guess I should mention that it's a '99 V6.
 

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Discussion Starter · #2 ·
This is kind of a bump, but also, here's what else I've found. While googling, and searching on this forum, I've ound that the codes given to the Autozone guy doen't necessarily correspond to the descriptions he gave me. For example, this post lists the P1136 and P1138 error codes as both meaning that my car is running rich. However, the Autozone guy said that the P1136 code means there is a fan problem and the P1138 means the car is running rich. Any thoughts?

Also, I'd not really known much about the fuel cap tightening - and would typically tighten it to 0 clicks - before starting to look into this and so now my fuel cap is much more tight 3+ clicks, and I was told that maybe that would account for the P0441 error code, but not the P0455 "large leak" error code. Thanks for any advising,
justin
 

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The P1136 Long Term Fuel Trim Add.Fuel,Bank1 System too Lean and P1138 Long Term Fuel Trim Add.Fuel,Bank2 System too Lean would be either vacuum leaks or a bad/dirty MAF. Also check for a plugged air filter. The snow screen was not plugged, but had a little dirt in it. Not enough to throw a code.

P0455 EVAP Emission Contr.Sys.(Gross Leak) Leak Detected and P0441 EVAP Emission Contr.Sys.Incorrect Purge Flow might be related, but I am not sure.

Check the gas cap (or just replace it). Also check the plastic tubes running under the car to the gas tank. The leak detection pump is under the driver's side rear wheel well cover ( I have never actualy seen it). Somewhere along the line there may be a break. Also check the purge valve (on top of the airbox) to see that it is clicking (it should).
 

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Discussion Starter · #5 ·
Boo yeah. I pulled that snow screen out, and the air filter wasn't like, terribly clear looking, but it didn't seem to be clogged, either. I'll pull it again in a few hours and take some pics.

The gas cap thing I was sure I'd fix by actually tightening it (since I'd not known the 3 clicks thing before getting the codes checked the first time) but yeah. I just got the codes checked again and same problems.

I checked the lines all the way to the tank and as far as I could see they looked fine. I'm not sure what the purge valve is or when it should click, but I'll look into it in a few hours when I get back from some other errands and while my oil is draining.

I'll run a bottle of fuel system cleaner through it, and keep poking around those lines and see if I can find something. I assume I just want to find a new MAF otherwise and see if that fixes it? Thanks,

justin
 
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