: 97 Catera Misfire on cylinder 3 help!!!



Wes123
02-11-13, 06:06 PM
hi i had recently bought this 97 catera that has been a nightmare i haven't had any problems with it until i got a oil change then i started having oil in my spark plugs several different things I've got rid of the oil in the plugs by replacing the valve covers new spark plugs and wires new coil pack and new cps senor new fuel pump and still i get a misfire which causing my car to run rough... its only on cylinder 3 the code p0303 is the code thats shows up on my scan tool any help would be appreciated:(

JohnJJO
02-11-13, 06:42 PM
Go to AutoZone. And rent u at tool call compression tester gauge. Do a compression test on cylinder 1,3 and 5. And see what reading u have . My cylinder #3 is low on compression but is running fine.

Wes123
02-11-13, 09:47 PM
Go to AutoZone. And rent u at tool call compression tester gauge. Do a compression test on cylinder 1,3 and 5. And see what reading u have . My cylinder #3 is low on compression but is running fine.I will try this first then report back do you have any idea of what a good compression reading maybe for this car?

JohnJJO
02-11-13, 10:32 PM
I don't remember what was mine. I need to look for it. But it was around 180-190psi. And my cylinder #3 is still like 150psi. U have to do compression test on cold engine. Just look at videos on YouTube how to do it.

retho78
02-13-13, 03:16 PM
Check the new plug and maybe change the spark plug wire.

JohnJJO
02-13-13, 03:50 PM
That's true, u can swap plugs between cylinder 1 or 5. Reset codes and then see if missfire came up one thouse cylinders, if yes, well that your wire, also u can preform resistant test on wire with multimeter. If wires good swap plugs. If its not plugs. Then u can run compression test. If compression test result good. That might be your injector.

Wes123
02-14-13, 01:02 AM
That's true, u can swap plugs between cylinder 1 or 5. Reset codes and then see if missfire came up one thouse cylinders, if yes, well that your wire, also u can preform resistant test on wire with multimeter. If wires good swap plugs. If its not plugs. Then u can run compression test. If compression test result good. That might be your injector.i think your right i didn't run the compression test i have pulled the injector an come to find out it was shocked so i pulled them all out and had them cleaned berryman injector cleaner i have order a new one a couple days ago an its suppose to be here tomorrow after i get that put in i will let you guys know how it went thanks for the help