Ok guys I need help and it seems my problem is too broad for a search engine. Was driving around town (having fun but not racing it) up and on ramp when my revs hit a brick wall and drop like a stone. CEL and traction light both come on and my car starts running like crap. I limp home and check the CEL with my accessport. My MAF sensor got wet when I went through an auto car wash. I let it sit for a day then clear the code and start it. Drives fine.

However a weird noise has been coming from the back ever since the CEL came on. When driving very slowly it makes a creaking sound like a squeeky door as the tires turn. It sounds like something was stuck on a patch of the tires. I go and feel both the rear tires and nothing, but the drivers side sits lower than the passenger side now. Not sure if that matters. The squeek turns into a judder on the highway and you can feel vibrations through the car that get worse when I slow down (both braking and just letting off the gas). I've obviously been babying the car but it drives fine aside from the noise/juddering. Any advice?

2005 6 speed manual with 51k miles. Just installed a midpipe and changed tranny and diff fluids, but that was on Monday, incident happened on Thursday. This is the only problem this car has ever given me so far.