Sup everybody, im new to this forum and I have a few questions. I apologize if this subject has been brought up many times before, but I just wanted to see if I can get a more direct solution before going to a mechanic.

My 1990 Honda Civic Si is running completely fine. Had a full tune up (oil, wires, plugs, pcv, fuel filter, etc) and recently had a Check Engine Light resolved after replacing what the code said I needed.

No check engine light was on UNTIL...i decided to clean up my battery terminals. I took off both the positive and negatives and put them back on after about 5 minutes. I started my car. Everything was going good and then a Check Engine Light comes on after 5-7 minutes of idling. However, when I start my car and drive it, sometimes theres no CEL the complete time im driving, and sometimes when I am driving the CEL comes on after about 15 minutes and/or with stop and go traffic.

What could be the problem?

 

you will need to pull back your carpet on the pass side and check the ecu code to know what code your throwing before you start doing any tinkering

 

Ive been trying to look at the ecu led when i turn my car just to ON. Of course, i dont know whats going on because theres no check engine light at ON. I tried the paperclip method as well but seems like no luck. Im hearing things such as i should go to a mechanic as soon as I get the CEL while I am driving and to not turn off the car so they can see whats up.