My daughter has a 98 mitsubishi eclipse 2.0.129,000miles she has replaced the plugs and wires, It has error codes p0171 and p0301 lean fuel, i have checked for vacuum and gasket leaks with brake cleaner no indication of leak any where have checked fuel injectors for continuity all around 14 ohms. I have erased codes but eventually come back, at first start will run and rev perfect for 3-5 minutes then run a little rough, if i turn it off and restart will run perfect, this happens on all restarts and after 3-5 min it returns to run rough. has new air cleaner, new o2 senors, new plugs and wires and have run lucas injector cleaner instead of taking rail and injectors out and cleaned manifold sensor. any help would be appreciated thanks for reading hoyze1@yahoo.com

 

this site sucks

 

You need to check those o2's with a scan tool for operation, it sounds to me that the car is going into "open loop" after a few minutes of running , on start up the car does not use o2's, instead it use's predeturmined air fuel mixture ratio thats built into the computer, thats why it runs good on startup.

You might want to take a look at Scannerdanner channel over on utube, he explains how these systems work! Look thourgh all his videos for o2 sensor testing! You wont be disappointed!


Good luck with daughters car!

Denny St. Louis