1997 civic short term fuel trim in the20s


New Member
I'm new to the group I have a 1997 civic with cold intake and headers my short term fuel trim is in the 20s at idle drops negative when driving. I have sprayed vacuum lines with carb cleaner also use propane around intake manifold and vacuum lines.didnt fine any leaks. Also disconnected the iac valve when disconnected idle goes up and down. Also no check engine light all monitors are complete. Car runs good just smells like gas fumes