P0300 - Multiple misfire - P1128 Upstream Heated o2 sensor swapped (Pending)

[GWerks]

Started up the car this morning, and felt a misfire, the CEL went on, and after a while it ws blinking. Came home, scanned it, code P0300 multiple misfire. Pull the plugs, cylinders 1-2-3 were black so running too rich, cylinders 4-5-6 were fine.

I dataloged the car, and watch the short term fuel trims, bank 1(black sparkplugs) was maxed out, bank 2 (clean sparkplugs) seemed to work fine. Tried switching the o2 sensors connectors, pluged the pre cat on the post cat and post cat on pre cat and nothing really changed.

I'm guessing it's a oxygen sensor? Any one have any other ideas?

Facts:

Bank 1 runs rich.
Bank 1 0xyegen sensor doesn't seem to read.

The misfire is not constant, seems to get better at times.

Where do I get that tool to get that o2 sensor out?

I scanned the car again and saw that the code P1128 is pending!! I know my 02 sensors are not swapped. I was thinking this could be an o2 sensor problem since only Bank 1 is running bad, but what now?

[MLJS4]

I have the same problem I changed my plugs and coil packs, alkso mass air and car still miss fires hard after 3k rpm idk wtf the problem is I have the same flaut code also

[GWerks]

Well, my car doesn't miss fire too bad. only some times, and it doesn't matter what rpm range is at. I'm thinking it's either the o2 sensor, maybe both of them on that bank, or CAT is clogged.

[97B518TQM]

Well, my car doesn't miss fire too bad. only some times, and it doesn't matter what rpm range is at. I'm thinking it's either the o2 sensor, maybe both of them on that bank, or CAT is clogged.

I hope you actually replaced all the spark plugs and you put the right ones in with the right gap. It could be a coincidence but ya, if all three of them are bad and the trim is abnormal then seems like an O2 sensor.

[GWerks]

I hope you actually replaced all the spark plugs and you put the right ones in with the right gap. It could be a coincidence but ya, if all three of them are bad and the trim is abnormal then seems like an O2 sensor.

I actually did. I just got done with it, so I put all the ones from bank 2 on bank 1.

And thanks! I'm starting to go crazy with this car, new problems everyday. Why wouldn't it throw a code for the o2 sensor being bad? Also, do I replace both or just the pre-cat one? Could it also be a clogged cat?

[MLJS4]

I gotta gutted downpipes, I'm ready to dump gas all over this car and lite it on fire I so sick of it I hate this miss firing shit I'm gettin mad talkin about it f**kin piece sh*it

[GWerks]

I gotta gutted downpipes, I'm ready to dump gas all over this car and lite it on fire I so sick of it I hate this miss firing shit I'm gettin mad talkin about it f**kin piece sh*it

Well easy there.

Do what I did. Pull all the spark plugs on bank 1 and look at them, then bank 2. I think my o2 sensor is bad, but I'm not sure yet.

[MLJS4]

Well easy there.

Do what I did. Pull all the spark plugs on bank 1 and look at them, then bank 2. I think my o2 sensor is bad, but I'm not sure yet.

I changed them idk if they went bad again I never worked on a car like this I hate I remove airbox y-pipe everything I like workin in space this motor is pure junk

[GWerks]

I changed them idk if they went bad again I never worked on a car like this I hate I remove airbox y-pipe everything I like workin in space this motor is pure junk

what part of MI are you from? read what I said. could be your o2s

[MLJS4]

Macomb, I don't know ill have to check it out

[GWerks]

Update^^

[osiris07]

Auto zone has an 02 sensor wrench for $10