On Friday, while it was very hot, my car lost power. Eventually went down to 30 mph with the pedal floored.
After a short rest on the side of the road the car ran properly again for about 2 minutes, then the same thing happened. While the problem existed and when parked, I could not rev the engine. RPMS would come up very slowly. At 3000 RMP the exhaust was loud and sounded like it was coughing. While running at 30 mph the exhaust was also loud and smelled very bad.

I took it to my mechanic and they gave up on fixing it because it is running fine now and the can't find any computer codes to diagnose the problem.

It clearly sounds like some type of relay that would effect the timing since the issue can go away as suddenly as it comes on. Can anyone share any more thoughts on which relay it might likely be?

Thank you.

 

I forgot to add that I have a 2001 Civic. Also, in the event that no one has any better ideas, I want to replace the main relay, but can't find any consistent information on whether or not I have one or two, and whether or not it is under the steering column or behind the glove box. Thanks again.

 

A main relay or ignition switch failure would shut the car down completely... not just reduce the power output of the engine. I suspect you have a clogged catalytic converter or partially blocked exhaust system.

 

there are 2 pgmfi main relays, they are under the glove box and theyre blue, it doesn't seem like that would be the case though, what trim is your car?

has the car every stalled? or does it just have no power?

 

Thank you. Could that cause the symptoms I listed? That the poor timing came on immediately, then went away immediately, then came back immediately?

Also, I did also discover the the loud exhaust I heard during the event was caused by the event. Apparently I was burning such a rich mixture that I burned hole through the catalytic converter.

 

It is an LX. (My relays are one blue and one brown. RC-5104 and RC-5009) not sure if one had already been replaced by a different one.

The car has never stalled. I had the single bad event that was significantly bad. The car immediately lost power, would not rev beyond 3000 rmp and then proper operation returned about 10 minutes later. 2 minutes into me resuming my trip home, it went bad again. By the time my mechanic checked it, it was fine again, has been fine, and no codes were recorded. Unfortunately, I know it will continue to happen unless I figure out what did it.

Thank you.