Rep Power: 0

just bought a 1996 civic automatic. check engine light is on and the only real issue i noticed is that right after you crank the car up it runs a little rough... not real bad like a bad skip, but definately skipping. if you rev it up it will clear up and run good or if you put it in drive and drive it, it runs excellent. will not skip again unless you turn the car off and crank it back up. no matter how long between turn off and turn on. anyway, im getting these 5 codes:

P1300 random cylinder misfire
P0302 cylinder 2 misfire
P0304 cylinder 4 misfire
P0118 coolant temp sensor
P0420 catalyst effiency

i dont THINK the headgasket is blown, it does not seem to loose coolant, does not run hot, runs very good, spark plugs are not saturated they are whitish grey color on the tips of all 4 of them. plugs and wires do not look very old at all. any help would be appreciated.

 
Rep Power: 518

Clear codes and see what comes back right away. Ignore the cat code for now, don't fix that until all other issues are resolved.

If the CTS code comes back right away, fix that first. An inaccurate or faulty temp sensor can make it start hard and run bad.

For the misfire, start the car when you KNOW it is going to act up. Shut it off before the idle clears up. Remove the plugs and see if they are wet, and see what they are wet with: Coolant, fuel, or oil?

Compression tests?

 
Rep Power: 0

i have a compression tester and fuel pressure tester... what does the compression need to be on this car? what about the fuel pressure? i see the car has a brand new fuel filter on it, which the guy told me he had put on there... maybe he was trying to fix a problem he couldnt figure out. ill put the temp sensor on there and clear the codes and see what happens and get back with comp. readings and key on engine off fuel pressure and key on engine running fuel pressure.

 
Rep Power: 518

Don't put a temp sensor on it unless it is a problem. Someone disconnecting it while the key was turned on is all it takes to set the code. Clear the code and see if it returns. THEN chase it.


You apparently haven't pulled the spark plugs like I said to in my last post. Do that. Do exactly as I said in that post. If the engine clears out and runs correctly before you shut it off, this check will be meaningless.


THEN, (depending on the results of the spark plug check,) run a compression test and post the results. Crank the engine until the compression tester stops climbing, then keep cranking for a few more hits just to make sure that's all it's got. Minimum 10 hits per cylinder.