: check engine help

10-08-09, 10:33 PM
My 2000 Catera has been giving me some problems as of late. the check engine light went on so I checked the error codes. It pulled up p0300-p0306, except p0305, all cylinder misfires. The thing is I just got a tune up a couple of days ago at a shop. I was thinking it could be the o2 sensor or a clogged fuel filter but I was hoping for a second opinion or a way to know if it was either of these parts. any help would be greatly appreciated.

10-08-09, 10:59 PM
oops i forgot some important info. The car idles rough, like it's about to stall. I also forgot to use the search button. Seems that it could be a bad gasket or coil pack also. I read that the coil pack can fail if oil leaked onto it. if true, that might be the case with mine since the oil sending unit needs to be replaced because its leaking. Is that an easy job to do? I'm trying to keep costs down. So far here's what I would need to do:

replace oil sending unit
check coil pack
check o2 sensor
check fuel filter
check gasket?

Here's the things I've already done:
tune up
cleaned throttle body

the maf was replaced in 3/2008, that's still good right?

im sorry if this seems so jumbled up, but this is just one of many things that have my attention right now. again, if anyone can help me work on this car that would be awesome.

12-09-09, 05:37 PM
it sounds like your having the same problem that I did. I had to replace the ignition coil pack. I would start there. order it off of ebay it will save you a bunch.