Still fighting code 171 174 any ideas???
Posted 01 May 2011 - 02:59 PM
Put it in shop they said fuel pressure at idle good but showing 25%lean,they found no vacuum leaks. Changed fuel filter. They were 95% sure it was mass air unit. I bought a new gm mass air for 300 bucks. They was wrong.
I read some about map sensors, so I reset codes unplugged map sensor. Truck physically ran better than it had in a long time. I run 180 miles and check three times. Only code came up was map sensor cause it was unplugged. No 171 or 174. So i thought hey thats it. I got a really clean map sensor from a salvage yard dont wanna spend 65 bucks and be wrong. Cleaned it with carb cleaner then installed truck coded withint 20 miles.
171 and 174 back. Filters a k&n and clean.
Other misc codes it originally had was random misfire po300 po102 maf.
Thanks for any help or thoughts in advance.
Posted 01 May 2011 - 03:05 PM
Posted 01 May 2011 - 04:02 PM
I had the same codes showing replaced the maf sensor and still showed ses code (171 and 174) finally figured out it was the rubber elbow directly behind the air intake above the throttle body. It looked ok but was just loose enough to let air in. Did a quiclie repair job with a couple of hose clamps and haven't had a problem since.
Posted 05 May 2011 - 08:21 PM
Posted 17 May 2011 - 08:58 AM
Posted 17 May 2011 - 09:43 AM
Fuel pressure was lower than 50psi?
Posted 18 May 2011 - 07:32 PM
Posted 18 May 2011 - 09:34 PM
I was having the same problems with it running lean and bucking on me a driving like total ass. After replacing the fuel filter and pump it still did it and it turned out it was a tear in the bonnet (top part of the intake that clamps to the throttle body).
Tiny cause, HUGE problems.
Posted 25 May 2011 - 03:16 AM
Posted 25 May 2011 - 10:21 PM
Talk about a sales plug
Edited by Slick1, 25 May 2011 - 10:21 PM.
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