just wondering if a bad cat can cause a CEL 1 code on an obd1 civic. also can a clogged cat cause idle surge? i have a friend who just put in a b16 into a crx. when you drive the car hard it has a bad rotten egg smell. throws a cel 1 when you drive it for a long time and also causes engine surge. let me know if anyone else has experienced this

 

A bad cat will normally fall apart and melt, and make the engine seem like it is making no power, even if the pedal is to the floor. Sometimes it can get so hot you can feel it through the shifter, and in extreme cases the vehicle can start on fire.

If it is still intact, the only way to really know if you cat is still good is to do a tailpipe test, and see if the cat is indeed functional on an OBD0/1 car.

Exhaust leak maybe? What kind of engine surge, rpm specific, how bad is it?

 

engine surge is pretty bad. from 1k to 2.5k rpm. what about the foul smell after acceleration? the car still pulls strong. just dont know why he would be pulling a cel 1 light.

 

Bad O2 sensor is what that code is for, is it hooked up and operational?

If you suspect the cat, pull out down and take a look inside, and see if its melting.

On deceleration, the injectors turn off once your foot is off the pedal and your still in gear, so nothing but air will be present in the exhaust, until you press the gas pedal.

Exhaust leak is the only thing that comes to mind.

 

If your o2 sensor is out then the A/F ratios are not right and the cat is getting overheated and causing the smell. The smell also will happen when your timing is not correct.

 

awesome. that could be the problem then. when his distributor went out we just bought a new one and slapped it on. it could be off a few degrees.