PO 171 and a PO 174

[baldtcc]

My truck heard me talking the other day of trading it in and what would you guess engine codes. lol What is the verdict on these codes hope it is an easy fix....

PO 171
PO 174

2001 SIlverado 4.8

[gavin05]

check for vacuum leaks and dirty maf.

[Beatdown Z]

To be correct, those codes are actually p0171 and p0174(in case you had trouble searching). I think they're the lean codes and they usually mean the intake gaskets are leaking.

Does your truck idle funny on real cold mornings?

[baldtcc]

Gavin I will try that I took off the maf about a month ago when I changed out the waterpump and cleaned out the throttle body and was it dirty. The insert wasnt there for the maf so It might be that i will have to check if the center piece is still in place or it is broke. Also I have about 160,000 miles and have never changed out the o2 sensors so I am guessing it is about time to do it. lol

Beatdown To be honest with you havent really noticed then again in houston it doesnt get cold lol but the other morning it did do something funny, it sounded like I had a mean cam loping really bad never died and after it warmed up it was fine. any suggestions.

[oleshifty]

Try turning the intake man bolts 1/8 turn, see if any are loose. Try cleaning the maf. Check for vacuum leaks.

I've had same code on my blazer now for a few weeks, truck runs great, so I haven't REALLY tried to fix it. Cleaned maf one day. Was bored today and replaced all the vacuum lines (is a 97...they were pretty dry rotted). The ls motors don't have much in the way of vacuum, but could be a pcv leak/etc.

I've never head of an intake gasket going bad on these trucks, but it's possible i guess. I'd try snugging everything first. Most likely maf related. 02s would only throw 1 bank. Not both. Probably still a good idea to change them, but i had my stock ones past 150k and never had a problem. Changed them JUST BECAUSE.

[gavin05]

those codes are system to lean bank 1 and 2.most of the time its a vacuum leak or maf dirty.if you find no vacuum leaks and clean maf then clear codes, if they come back then run some fuel system cleaner.the bg fuel system cleaner is the best.more than likely one of those is your problem.

[Beatdown Z]

I chased the intake gasket problem on my '00 4.8 for two winters. Finally changed the gaskets and no more erratic idle on really cold mornings and no more lean codes.

1) http://www.fullsizechevy.com/forum/g...any-ideas.html

2) http://www.fullsizechevy.com/forum/g...ine-light.html

3) http://www.fullsizechevy.com/forum/g...-stalling.html

[Razgriz1]

I'm having the same problem and also getting p1133 and it will not idle at all on cold mornings

[Beatdown Z]

I'm having the same problem and also getting p1133 and it will not idle at all on cold mornings

P1133 could be caused by a few different things. Intake/vacuum leaks, exhaust leaks, headers dissipating too much heat, RTV used on exhaust gaskets...

Here's some threads:

http://performancetrucks.net/forums/...ighlight=p1133

http://performancetrucks.net/forums/...ighlight=p1133

http://performancetrucks.net/forums/...ighlight=p1133

[baldtcc]

Thank you for all the input I will give it a try and see what happens and repost if good or bad happens.