3800 Help, SES p0170, lean.

joeyboy777

Regular
Mar 2, 2008
163
12
I have been throwing code p0171 for the last 5 days. I need help figuring it out. What did you guys who threw the code do. Ron has put up some tips on what to do. I did some of them, I am looking for more information I guess.
The car runs crappy at idle, there is a sound like it is about to die. i need to give it gas at lights sometimes, the idle sounds like the engine is running out of gas. It seems the cable to the throttle body is loose. I pull the throttle a bit towards me as i am standing over it. It stays at the higher level.. where it sets. The engine will sound better for a little. I will try tightening the cable at lunch.
Ive done so far:
1. cleaned out throttle body and cai.
2. pulled off egr, there is a LOT of carbon buildup. I cleaned it as much as I can and put it back on. I did not hear any noises or anything else from it. I am not replacing at the moment because my dealership wanted $210 for a new one.
3. Changed the pvc valve.. mine was dirty
4. reset the battery.
5. Checked the spark plugs, they are pretty dark, but also pretty old.
6. Checked all connections except for hard to reach. did not check the o2 on the headers... this could be the issue.
Would a pcm update be able to remove the first bank o2 sensor, the one on the headers. I will ask beyerch tonight.

What else needs to be checked out. My car is still running like crap
thanks,
joe a
 
I

imported_Ron Vogel

Guest
First off, don't remove the front O2 sensor code. More than likely this is a gasket or EGR leak. What has been done to the top end of this motor? That's the question you have to ask to diagnose. The only gasket that will up and fail really is the SC to TB gasket, and I'd check that first. The vac line off the tb tends to split, and I'd check that out too.
 

joeyboy777

Regular
Mar 2, 2008
163
12
OK... I will check the vacuum lines, there may be a split. I have not done much motor wise. My latest items added are headers, open cone cai for the moment, and a new trans. I have not touched anything around the tb or supercharger. Maybe when the headers were getting done we may have damaged a line. is there any way to check these, the ones that arent easily visable?
I will check and post some pics tonight.. I need to fix this.
joe a
 
I

imported_Ron Vogel

Guest
Originally posted by joeyboy777@May 26 2004, 01:22 PM
OK... I will check the vacuum lines, there may be a split. I have not done much motor wise. My latest items added are headers, open cone cai for the moment, and a new trans. I have not touched anything around the tb or supercharger. Maybe when the headers were getting done we may have damaged a line. is there any way to check these, the ones that arent easily visable?
I will check and post some pics tonight.. I need to fix this.
joe a
I tried propane on JET's car around the EGR, and it didn't raise the idle, but you could hear something leaking. I cupped my hand around the EGR tube at the EGR, and it amplified the sound enough to pinpoint the leak. The EGR tube is a little fragile, and if a leak springs up between it and the intake LT fuel trims will spike causing that code. I believe the tube is around $25 from the dealer if you need to replace it.
 

J.E.T.

TCG Elite Member
Nov 10, 2008
1,319
0
Adding more fuel will not solve this problem, you need to fix it, not bandaid it.

A P0171 can definately be a low fuel pressure problem!! If it's a not vacuum leak or an exhaust leak - then what else could cause a P0171 !?! That's why its rightfully defined as P0171 LEAN because of the possibility of low pressure.

If indeed he has an exhaust leak before the front O2, then you are correct in stating that adding fuel is a bandaid.

J.E.T.
'97 Red GTP
 
I

imported_Ron Vogel

Guest
Originally posted by joeyboy777@May 26 2004, 02:31 PM
how about this, http://www.zzperformance.com/zzp/products/...im_blockoff.htm
If it is indeed the egr, could/should I just get this.  I would have it in about the same time as getting the tube for the egr.  any opinions?

joe a
That blocks off the exhaust side of the EGR, and you would still have a leak between the EGR and the intake manifold. Plus, blocking off the EGR isn't for everyone...It brings on a whole new set of tuning problems. I have mine blocked off, but I wouldn't suggest it unless you are doing it to reduce carbon. It really won't hurt performance until you get heavy in the modding.

OOPs, just noticed that's the whole kit...I believe Auto Dummy has one, you may want to contact him on how it's working out.
 
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