Just bought this hatch with this problem. anyone know what can be the problem for these codes? i live in california and i need to smog it asap. been passed due. to my thought it was the cat that needed it to pass smog cause the previous owner showed me his smog results and it passed all emissions but failed cause the cel and cause he didn't have a carb sticker on his aem intake. So today I changed the catalytic converter with a good used one without cracks (cause the old one had a crack where the first o2 sensor was at) and i test drove it for a good 10 mile run, and cel didn't come on at all. Its ran smoother and stronger so i thought that fixed the problem but right after i got home and changed to go out, I went around the block and the cel came back on with the same codes. spark plug and wires looks good. they looked like they were changed not too long ago. the car idles funny when cold start (like its misfiring/bogging) but fine once warmed up. No black smoke. other then that, it runs great. greatly appreciated if someone can point me in the right direction as i don't know what to change out next. thanks in advance.

--I also smell gas from the tailpipe when the car is on if that makes any difference.

unknown miles on motor as it has a Si cluster with 132k miles

did a compression test

cylinder 1=115

cylinder 2=150

cylinder 3=165

cylinder 4=175

 

Cyl 1 is severely low - that's a red flag right there.

Start by replacing your cap, rotor, and wires. Also do a valve lash adjustment. Reset the ECU, do another compression test, and see if that helps at all.

 

pull out spark plug wires from cyl 2 &4 check to see if they are drenched in oil.
if you have money do a full tune up if not check resistance in the wires and insulation.

 

thanks guys. i found out yesterday that the cat that i just bought was a bad cat. it had a crack too so i used my snl cat from her 97 lx. after installing it i gave the motor a valve adjustment. got everything adjusted and installed and bam, this hatch is running like a beast. I went to go smog it yesterday afternoon and it passed ca smog. So thanks a lot you guys for the good info.

for the next person who is searching and have these cel codes, just check the cat for cracks, these cats are known to crack like shiets and hard as hell to find a good used one cause its too expensive to get a new one. a good cat will clear the cel. also do a valve adjustment if its been a while.

will do another compression test today to see if the numbers are different.