CEL on again

[fish92]

Ok so my truck started idling rough and check engine light came on the other day so today I went into auto zone to get the codes and it came back as code 172 which is #1 lean mixture or something to that effect and the guy told me that it was probably the MAF sensor so I bought a can of MAF cleaner and brought it back home and took it apart and cleaned it and checked my air duct for cracks but didnt find anything and then I turned it on and the idle seemed to be smoother and the CEL was off but then i got in it and started driving and about the time it got up to normal operating temp the CEL came on again. any other ideas on what it could be? or should I just get a whole new MAF sensor? I just replaced the air filter in june so im pretty sure that doesnt have anything to do with it.

 

[hvacken]

Had the same problem, did the MAF thing, turned out to be the O2 sensor. I'd try that before buying a new MAF.

 

[modelageek]

Ok so my truck started idling rough and check engine light came on the other day so today I went into auto zone to get the codes and it came back as code 172 which is #1 lean mixture or something to that effect and the guy told me that it was probably the MAF sensor so I bought a can of MAF cleaner and brought it back home and took it apart and cleaned it and checked my air duct for cracks but didnt find anything and then I turned it on and the idle seemed to be smoother and the CEL was off but then i got in it and started driving and about the time it got up to normal operating temp the CEL came on again. any other ideas on what it could be? or should I just get a whole new MAF sensor? I just replaced the air filter in june so im pretty sure that doesnt have anything to do with it.

what engine do you have? p0172 is lean on bank 1(passenger side). if you are only getting the code for that side it most likely is a vacuum leak/exhaust leak on that head. if you got both lean codes that would indicate maf, fuel pressure....

*forget this post i must have been drunk....I was wrong

 

[fish92]

Its the 2.3 and yea that was the code and i know that there is an exhaust leak between the manifold and the cat but that has been there since i have had the truck so i dont think that it would cause the CEL to come on just now after it had been off for a month and nothing else causes me to think that it is a vaccum leak so im kind of wondering if it could have something to do with the idle control arm because ive heard that those are notorious for going bad. thanks for the input.

 

[modelageek]

sorry i was not paying attention. we are in the 4 banger section and you have a rich code not a lean code............ I would suspect the MAF( as posted earlier) and I would pull the vacuum line off of the fuel pressure regulator, it is on the fuel rail and see if there is fuel in it........if there is it is bad........ if not consider a fuel pressure test.

 

[modelageek]

other possible causes ect sensor, dirty air filter or clogged air intake (* i see you did this already), bad 02 sensor, as stated earlier.

 

[fish92]

It came up as code 172 which is lean bank #1 which is what they told me at auto zone and i just looked it up in my chilton

 

[modelageek]

It came up as code 172 which is lean bank #1 which is what they told me at auto zone and i just looked it up in my chilton

p0172=system to rich bank 1, p0171=system to lean bank 1

 

[fish92]

p0172=system to rich bank 1, p0171=system to lean bank 1

look at the OBD I codes its a 94 not OBD II

 

[modelageek]

look at the OBD I codes its a 94 not OBD II

ok my bad..........again...........i will sit this one out before i screw it up anymore....

 

[fish92]

Alright I found a possible cause of this problem i looked under my hood today and noticed that there are 2 hoses coming from the pressure feedback sensor that go down to the pipe that leads up to the EGR valve from the exhaust manifold and the one was hanging off and I looked at it and noticed that it was split and so i took it off and went to replace it with a new one only to notice that the smaller pipe that it was supposed to be hooked up to was about half broken off so now I get to replace that whole pipe which is not a huge deal because I have a spare one but just a pain in my ass

 

[fish92]

ok so i replaced that and my CEL went off for a while and would just come on for about a minute and then go back off for a couple days and then it got to where it came on and stayed on so i got the codes and got the same one (lean bank #1) and tonight I cleaned the IAC valve with carb cleaner and replaced the O2 sensor and started it up and the check engine light came on again but i drove it and it ran better than it ever has and idled smooth but then i let it set for about 10 mins and went back to it and started it up and it was idling really rough and i reved it and it idled back down and idled rough again for a few seconds and then died and i started it back up and it did the same thing but then when i reved it it started idling smooth again and i reved it a few more times and it would randomly go between idling smooth and rough. I have no idea what else it could possibly be and any and all advice is welcome. thanks