Hello all, I''m new here, actually don''t own a Trooper but I promised my friend I would try to fix his for him while he is working overseas for the summer. However my knowledge on these is limited so I''m hoping you guys may be able to give me a push in the right direction, I don''t want to just start throwing parts at it unless it really needs them. [img]smileys/smiley2.gif[/img]

It''s a 1998, I''m almost positive it has the 3.5L V6 in it, was running real rough for awhile and starting to get worse shortly before he left. Sometimes stalls at idle and the check engine light is always on so I took it down to the local auto parts store and pulled the codes, came away with quite a list:

<ul>[*]P0102: MAF or VAF A Ckt Low Input[*]P0121: Throttle/Pedal Position Sens A Ckt Rng/Perform[*]P0171: System To Lean Bank 1[*]P0174: System To Lean Bank 2[*]P0303: Cylinder 3 Misfire Detected (This one worries me a little)[*]P1404: EGR Ckt Rng/Perform Malfunction[*]P0405: EGR Flow Sensor A Ckt Low Input[/list]I''m thinking a good cleaning of the EGR sensor/valve should hopefully clear up the last two codes, I''m not really sure what to make of the system lean ones. If anyone knows a good step by step for the EGR it would be helpful, I did search but didn''t come up with much. The guy at the parts store recommended replacing #3 coil pack but I''m really trying to avoid that unless absolutely necessary since they''re $150 each at Napa.

Any ideas where to look/check first for some of this stuff? I feel bad because I sold it to him, ran great for the 3 months I owned it and I thought it was in great shape when I sold it to him but a few months later he started having trouble with it. Any help is greatly appreciated. [img]smileys/smiley1.gif[/img]

 

I think this happened to me also...the way I was able to fix the issue was to replace the TPS (10$), the IAC (20$), clean the MAF sensor..spray it with a cleaner. Take out the EGR, clean it out with also with a cleaner...

Also, if the car has not had a tune up in a while, install new spark plugs, oil change it, clean out the air filter (just tap it against the wall or a clean ground to rid of the dust that collected).

reinstall everything....run the car out on the highway for about 40 mins to reset the computer automatically. check the computer using the scanner at the autoparts store and see if there are codes left.

Try it and let everyone know if it worked.
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