running lean ??

[wukash]

i have a 1994 trans am about 6 months ago my car was running wierd once it had warmed up. i replaced the 02 sensors and it ran fine till yesterday. once the car warms up (roughly 20 min of driving) it starts missfiring and throws a engine light on... i had the computer scanned at a buddies and its throwing codes 44 and 64 which is the 2 02 sensors and it says they were picking up a lean mixture... now my question is could this all be due to the reason i cut out my catalitic converter and dont have a 3rd 02 sensor ? i didnt think it mattered on a 94

[psychoticLS1]

Have you checked for any exhaust or intake leaks....sounds like you might have some unmetered air getting into the engine or exhaust system

[wukash]

it only seems to happen after 20-30 min of driving ... could this still be an intake or exhaust leak ?

[hotrod18_69]

No it wouldn't matter that the cats gone.. Have you checked the fuel pressure yet? and ideal and at WOT to see if it drops off under a load.. Could be a bad fuel pump or maybe the ground next to the batt.. not letting enough votage to the pump.. All something to check..

[Chad97z]

if you have a custom program in the computer, I'd set it back to original then clear the codes, then rediagnose your problem. (Unless you have hypertech programming - I know they dont mess with fuel mixture at normal operation)