Hey BF....riddle me this.

96 SSEi is throwing a code. P0171 For those of you who don't know its the fuel system leaning out because the Bank 1 O2 sensor has detected too much oxygen in the exhaust

I recently replaced that sensor. So I jumped to the MAF to see if it was faulty. It was so I replaced it. Problem solved....for 3 weeks. Code comes back. So I removed my stock air box with the oiled K&N Filter in it and installed a cone. Cleaned the sensor. Problem solved. 2 weeks later...you guessed it P0171 is back. So I'm confused and feel something like this dh2

Could my intake hose have a small enough hole that I am not noticing or what? Or should I start checking the vacuum lines? My only problem is the car is running strong so to me, if the vacuum lines were bad I feel like I should notice.

Some advice would be great.

Thanks, Ninty9

Check the tech info area, you will find OBD2 trouble shooting. You will find the p0171 code there and there is a list of things to check. Start with that.

Have you done any mods to it. I would check you fuel filter. Check you Fuel pressure. Might have a faulty fuel injector. Btw if you want to ask me to a dance bring flowers.

While checking techinfo is the best place to start. This code is a fun one. I've mastered it and that'* not an easy thing to say.

Please search my username and P0171 if you want to help me out from typing it all again.

Has the LIM gasket been replaced?
Have any vacuum lines been disturbed?
Has the battery been unhooked or changed?

Once you search on the code, you'll understand better. I'm pretty sure I've written explanations to it all. Heck..I'm off to search it for you. be right back.

Here'* one https://www.gmforum.com/showthread.p...ighlight=p0171 Covers a good amount.

Come on guys, he has a oiled air filter.

He'* telling us that he thinks that was the cause of the maf dying the first time. But he'* also saying he knows how to test maf'* and this one isn't dead or dirty, with a new/different filter in front of it.

Those were my reasons for looking elsewhere.

The problem with p0171 is there'* a 100 different things that can set it off. Unmetered air entering the engine is nearly always the cause. Getting past a dirty MAF, a vacuum leak, a exhaust leak.

Checked all the vacuum lines behind the MAF, and they are all in good condition. I may need to change them down the road but as for right now the lines are not the problem. I went ahead and put her on the lift to check the exhaust system, because I'll admit I would never have thought of that, and everything looks good there. (Even though it would look so much better with a better system >). I understand that there are way too many possibilities of this code being tripped. But when put into the situation, is it easier to solve a problem with 1 person working on 100 possible solutions for 1 problem....or....100 people working on 1 solution each for the same 1 problem.

Make sure you also check your EVAP lines, and your EGR tube. O rings on the injectors, LIM gaskets, PCV valve. This code generally comes for a air leak between the MAF, and the O2 sensor.

Will do. Thank you.