I have replaced the map, maf, sensors and the spark plugs, need it to pass emissions
Are there any codes? do you hear and vacuum leaks? have you replaced the idle air control valve
SOURCE: follw-up
check the mass air flow sensor if still no spark check the coil packs for power if they dont have power check all fuses and relays if they are all fine look for a short
SOURCE: '01 Bonneville that misfires only at idle
Its either an intake or exhuast lobe that is worn down on the camshaft or a bent pushrod or a worn lifter.I would first check the rocker arms for looseness then check the pushrods for that cylinder to see if one of them are bent.It may only need the valves adjusted.
SOURCE: 1993 pontiac grand prix 3.1 liter
the 3.1 had some EGR problems, EGR valve stuck open, blown diaphrams, Plugged passages Im not saying that is all your problems and I believe yours has whats called a linear EGR about $350.00 from the dealer (and that is the only place you ever consider buying such a critical part for the emissions system regardless of the cost)
That car is so antiquated as far as computers go that relying on the codes is nearly pointless! Map code can set because of low engine vacuum which you will have with a poor running engine, Check for 5 volt reference voltage at the TPS and MAP with the key on and engine off if no 5 volt reference I suspect a Computer. Computer Ground is on the Thermostat housing and needs to be clean and secure.
There is a legit test in the GM factory manual called the TAP TEST take the ECM (computer) and slap it with an open hand, if the symptoms change the ECM is bad it's very common in the early-mid 90s for the computers to go bad in one way or another the circuit boards come loose and suffer also from cold solder joints.
Make sure the wires are on the correct plugs and hopefuly you used factory plugs and wires and No split fire or bosch plugs only AC delco
Make sure you have good spark on all 6 cylinders.
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You can clean the EGR. No promise it will work. I have an idle problem on my `97 Grand Am Se. Shop told me I could clean it and it might solve my problem.
Just remove the EGR with the 2 bolts from the top of the manifold behind the throttle body if you have a 3.4 v6 like I do. Then leave it upside down with throttle body cleaner in it. Fill the EGR level with cleaner and let it soak for at least 30 min or more. Then reinstall.
This will remove any carbon on the inside which plugs the needle from pushing out at highway speeds. Hope this helps. If the problem returns in a week or so then replace with new EGR. New EGR is about $100-200! Cleaning seems to have helped my car did that about 3 weeks ago.
If you have a service engine light on turn the key to the run position on the ignition, pull the fuse to the ECM (batt) and disconnect the wire harness to the EGR. Reinstall it after a 1 min, That will clear all the codes in the ECM and reset everything.
Once you place the ECM fuse back in, start the car. It may stall but let it, DO NOT TOUCH ANY THING. The ECM need to relearn the EGR and engine from all it's sensors like the first time it was started. Just start it up again and it should be like the day it came off the assembly line and will relearn everything.
Good luck and just drive it like you always. If you decide to change the EGR valve, you still need to clear the ECM as mentioned above for the ECM to relearn the new EGR valve. Hope this helps and keep me posted.
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171,174,175,300
codes po171,po174 and po175 are for your o2 sensors. both need to be replaced. and po300 is a miss fire that is your ignition control module
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im going to replace the egr valve and all 3 o2 sensors today, i hope that works
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