CEL came on got a couple codes

[jeffnoel]

P0171 & P0174 System 2 lean banks 1 & 2.

The light came on yesterday while the wife was driving her 02 GT. Plugged in the Predator this morning and these are the codes it's showing. I have done a search and looked around for vac leaks couldn't find anything obvious, but I did notice the soft hose coming of the PCV valve was cracked.

I haven't made any mods in a long time that's not the cause. The car has almost 90K miles on it. It's been a while since I changed the fuel filter (about 25K miles ago) and have never changed the PCV valve so I will do that today. Also will pick up some electronics cleaner spray for the MAF since I've never cleaned that either.

Anything else I should look at?

 

[Skidzz]

Are you noticing any difference in the way your car is running? Generally, if there is something wrong with your PCV valve, the car will idle rough. I think there is a sticky somewhere on SN with all of the codes and what they mean, unless it got taken down or something.

Edit: My mistake, I just noticed that you already know what the codes mean. I'd say check that PCV valve one way or the other. You might want to check plugs, wires, fuel pressure, etc. also.

 

[jeffnoel]

Wife says the car idles and drives normally.

 

[lazerred02]

Wife says the car idles and drives normally.

Did you try to clear them with the predator? If not do that and take it for a test drive and see if they come back on. Some codes have to be dectected more than once before a CEL will come on, so maybe do like 3 different test drives. If it still comes on after clearing them then start digging, but sometimes these cars throw codes.... you clear them and then it's gone. Just something to try before you tear the car apart.

 

[jeffnoel]

Yeah I cleared them this morning right after I pulled them, I haven't checked with the wife to see if the light came back on or not. But I did hear it run this morning as she left for work and it started, idled and sounded normal as she sped off to work.

Picked up a fuel filter and will install that tonite and see what happens. I been meaning to do it anyway just hadn't gotten around to it.

 

[tank_567]

you need new front 02 sensors

 

[lazerred02]

you need new front 02 sensors

Your certain of that? Kinda hard to troubleshoot his car over the internet isn't it?

 

[lazerred02]

Yeah I cleared them this morning right after I pulled them, I haven't checked with the wife to see if the light came back on or not. But I did hear it run this morning as she left for work and it started, idled and sounded normal as she sped off to work.

Picked up a fuel filter and will install that tonite and see what happens. I been meaning to do it anyway just hadn't gotten around to it.

Yeah I would check it and see if it did'nt come on I would wait until she makes two more trips with it to see if it comes back on or not. Def. not a bad idea to change the fuel filter anyways since you have not done it in awhile it seems. Good luck man.

 

[jeffnoel]

Yeah it came on (SES light) about half way through the day on her. I just changed the fuel filter and pulled codes again. It came back with the same P0171 & P0174 as before but a couple new ones also P1130 and P1150 (lack of H02S21 switches - fuel trim at limit). I cleared them all again and will see if changing the fuel filter did anything. I still need to get some electrical contact cleaner to clean the MAF too.

 

[jeffnoel]

OK, fuel filter wasn't the culprit the light came back on yesterday with the same 4 codes now. This morning I removed the MAF sensor and cleaned it with some MAF cleaner from CRC, it did look like the wires may have had something on them before I cleaned them. I reinstalled it and cleared the codes again so let's see what happens now.

 

[Robs96]

Bad maf sensor. Cleaning a bad one wont fix it.

 

[jeffnoel]

I don't know that it's bad yet (so how do you), I haven't heard from the wife to see if the light came back on today.

 

[Robs96]

If it was just one bank, it would be something else, something o2 sensor wise. Both banks are running this way because the air meter is not reading right and the computer is running this way to compensate fuel for the loss of air readings. Also, I've had this problem myself and after testing several things, the maf didn't pass the test. A new maf solved the problem. However, a manifold leak or other air leak of sorts can also cause this problem. Try using carb cleaner or propane (heating torch, gas only no flame) and run it around different areas of the engine with it running and see if the engine responds. IF that happens, an air leak. And check for rotted vacuum hoses. Either way, hope this helps and good luck. Do post the solution to the problem if you would when you get it fixed.

 

[03ghoststang]

Yeah it came on (SES light) about half way through the day on her. I just changed the fuel filter and pulled codes again. It came back with the same P0171 & P0174 as before but a couple new ones also P1130 and P1150 (lack of H02S21 switches - fuel trim at limit). I cleared them all again and will see if changing the fuel filter did anything. I still need to get some electrical contact cleaner to clean the MAF too.

it could be the O2's cause i had a taurus a few days ago at work with the same codes. I datalogged it the O2's stopped switching from lean to rich and the voltage stayed low meaning that it was detecting a lean condition .......anywho i changed them out car ran great havent had it comback or anything so i am hoping it was that

 

[Robs96]

it could be the O2's cause i had a taurus a few days ago at work with the same codes. I datalogged it the O2's stopped switching from lean to rich and the voltage stayed low meaning that it was detecting a lean condition .......anywho i changed them out car ran great havent had it comback or anything so i am hoping it was that

I would test the maf or have it tested by someone. Both banks? Both upstream sensors? All four sensors? I don't think o2's. When I had an o2 go out in my 96gt and later in my other, a 95 v6, both cars ran like complete ####. Like I said, had the same problems, maf was the fix. Or vacuum leak or faulty gasket. As for more than one o2 going out at the same time, especially both sides, I will concede, stranger things have happened.

 

[jeffnoel]

No vac leaks, car idles and runs normal.

How do you test a MAF?

 

[Robs96]

Alright, do you own a multimeter and have working knowledge of how to use it?

 

[Mike97gt]

you need new front 02 sensors

So many people even so called professional ford techs think that so ford issued a TSB warning that replacing the 02's will not fix this problem.

The chances of both sensors going bad at the exact same time is extremely small.

Your certain of that? Kinda hard to troubleshoot his car over the internet isn't it?

If you have the right info from somebody you trust then you can diag, other than that it's a guess... some people will guess better than others if they have a better working knowledge of EEC.


BTW to the guy with the problem.. Did you ever fix the cracked PCV hose.. That can and will cause these codes.

 

[lazerred02]

So many people even so called professional ford techs think that so ford issued a TSB warning that replacing the 02's will not fix this problem.

The chances of both sensors going bad at the exact same time is extremely small.



If you have the right info from somebody you trust then you can diag, other than that it's a guess... some people will guess better than others if they have a better working knowledge of EEC.


BTW to the guy with the problem.. Did you ever fix the cracked PCV hose.. That can and will cause these codes.

I know that you can diaganose it if you have the correct information without even having the vehicle in front of you, I too have been a professional mechanic for the past 9 years....I know a thing or two It' just that the guy giving him these solutions seemed to be pulling them out of nowhere and I would hate to see this guy waste his money swapping parts because some random guy on the internet told him to do so.

 

[2002BLGT]

No vac leaks, car idles and runs normal.

How do you test a MAF?

Did you fix the cracked PCV hose ? that would cause the codes , and also how many miles are on the car , if its around 80K or more you might want to put a plenum gasket ( o-ring ) on it , I had an explorer that did the same thing you are talking about for months and it was the O-rings on the upper plenum that I finally fixed it ......