04 6mt sedan. Car sat for two months because of issues with a **** mechanic who doesn't ever show up to work. New OEM cam sensors installed. New plugs 5k miles ago. Cleaned maf, throttle body, and k&n filter at the same time. Got the car back, drove it home 3 minutes and had no problems. Immediately tore it apart and installed a sub and amp. Getting power from where the positive terminal bolts onto the fuse holder thing. Made my own grounds in the trunk with wire wheel/nut and bolt. Drove it around that night for over an hour with no issues. This morning, drove the car for less than 10 minutes to get hardware to mount the amp and capacitor, notice a little bucking during acceleration. It sits a few hours, it snows 2-3 inches, I shovel it out and start it. The bucking got a little worse, drove it less than 10 minutes again and the SES light comes on. P0132, P0138, P0152, o2 sensor bank 1 sensor 1, bank 1 sensor 2, bank 2 sensor 1 all circuit high voltage. P0158 bank 2 sensor 2 was pending. Cleared them, turned around. Car starts running very poorly, bogging like crazy any time I gave it even a little gas, then it would randomly clear up and accelerate for a second or two. By the time I got to the corner by my house it was missing bad, SES light flashing. Pulled into the driveway and shut it off. Ran the codes again, all the o2 codes came back and got P0175 bank 2 too rich and P0300 multiple random misfire. Restarted it and it ran fine just free revving it not moving. Waited another few hours, started it and it was stumbling just trying to idle. Was going to replace the crank sensor because I just had it sitting around, but the plug came off with the old sensor so I now have to wait for a new pigtail before I can do anything with testing. First time I've driven the car in the snow, mechanic also said there was a code for an intake air temp sensor that I never saw. Figure the missing and too rich is just a result of the o2 sensors freaking out. Any ideas why all 4 at once? Would one going bad **** with the rest of them?

 

They didn't all go bad at the same time, literally never seen that EVER happen.

However people like to just throw parts at a car hoping something will fix the issue without actually getting out the oscilloscope to see if the sensors are actually working or not.

Since it ran fine BEFORE you were making electrical modifications I strongly recommend you uninstall all your wiring and see if the problem still persists, you may find that something was improperly installed or missed like not tightening the battery terminal or such. Maybe a bad electrical component in the new install is leaking voltage to ground and screwing up the entire chassis ground system.

Since the CKP harness broke off on the sensor it was obviously bad, may have caused a cascade of other failures like those CMP codes.

Just to verify you DO have the engine lower cover installed when driving yes? Getting water in your computer never ends well.

 

Got pissed at the car and parked it for a month and just started trying to drive it again. Crank sensor code is definitely from a damaged flywheel, repaired the harness and new oem sensor installed, found more debris inside the bell housing. Ordered a czp lightweight flywheel and a new clutch and will do that soon. Car was fine most of the time besides hard starts from the crank sensor issue. Until today, when it rained again, and all of these symptoms came back. So its definitely a water intrusion thing. This car has been in at least 4 front end accidents and has almost no plastics remaining whatsoever, so whatever cover you are referring to is definitely gone. I had to buy wheel wells for it when I first got the car it was that bad. If you could point me in the right direction as to what cover you are talking about so I can try and get one that would be great.

 

I would start by getting the battery box all weathered back up. Remove the cover over the battery (not just the access window but the entire thing) then disconnect/remove the battery. Behind it is the engine bay fuse box called the IPDM, it should have a weatherproof cover over it that might be missing.

This chassis doesn't actually have a front cowl below the windshield that would catch and divert water off the window, it is a cowl-less design and everything in the front MUST be waterproof because it WILL be getting drenched in water.

There is a drain below the battery that is prone to clogging up and then filling the entire battery area with water and submerging the IPDM, this is mostly a problem when people get a lot of leaves and such on their car and don't clean them off, they turn to mush, they plug the drain, bad things happen.

It's also possible you are getting water seepage into the cabin that's saturating the ECM and/or BCM. Check your floorboard carpet to make sure it's not wet.