Question about 1996 Pontiac Sunfire
Changes made so far: O2 Sensor, map sensor and air intake control valve, cannot detect any vacuum leaks, plugs and wires are new, firing order correct. new thermostat.
uses fuel like crazy, exhaust smells, after clearing code car runs for a few days, then starts acting up and engine light comes back on,
Also having a hard time clearing the drive cycle in the computer for emissions inspection. 60,000 miles plus a few.
Any help is appreciated! Thanks
Here are some possible causes, I would start with anything related to replacing the intake.
Air leaks in intake manifold, exhaust pipes or exhaust manifold
Fuel control sensor is out of calibration
Low fuel pressure (fuel filter clogged, pressure regulator failure)
One or more injectors restricted or pressure regulator has failed
O2 sensors contaminated, deteriorated or has failed
Vacuum hose is disconnected, broken, leaking or loose
Posted on Jan 28, 2009
Posted on Feb 14, 2009
Bank 1 is the frt side exhaust manifold (did they say bank 1 sensor 1?),you can start by replacing that sensor,i would check the intake for leaks ,the gm 6cly. are known for bad intake gaskets,you will see oil coming out form the frt or rear of the intake,also check your atifreeze overflow bottle for bronwish sludge,which means that the oil is mixing with the antifreeze.A leaking intake could cause that lean condition.
Posted on Mar 29, 2009
oxygen sensor, vacuum leak, and yes it could most definitly be if you swaped the wires of the firing order accidently you will get a code p0171 Check the tubing going from the air filter to the intake manifold to see if it has come loose. This might account for extra air going into the intake manifold than the computer is aware of. Otherwise it may be due to a faulty(or dirty) MAP/MAF sensor. Another possible cause is from low fuel pressure due to restricted fuel lines or a bad fuel pump.
Posted on Jul 28, 2009
I would check the O2 sensor, and if it checks bad, replace it, and clear the trouble codes. If the light comes back on, you may need to check further. .
Posted on Oct 28, 2009
Tips for a great answer:
Feb 12, 2015 | 2002 Ford Escape
Feb 18, 2012 | 2001 GMC Sonoma Extended Cab
Oct 12, 2011 | 2000 Ford F150 Flareside SuperCab
Oct 12, 2011 | 2001 Chrysler Town & Country
Oct 04, 2011 | 2004 Chevrolet Impala
May 21, 2011 | 2001 Jaguar S-Type
Apr 27, 2010 | 2000 Saturn SL
Nov 01, 2009 | 1999 Isuzu Rodeo
Sep 18, 2009 | 1997 Pontiac Bonneville
Nov 23, 2008 | 1998 Buick LeSabre
625 people viewed this question
Usually answered in minutes!