Car stumbling. Cel.. Bad gas mileage. help!! :[

[Khrysus]

Alright so i'm new here. I just acquired a 2008 MS3. The freaking thing only has 19k miles and i've had it for about a month. Ran perfectly amazing and fine when I first got it. It started out with the CEL giving the the codes:
P2177 System too lean at idle, bank 1,
P2187 System too lean at idle, bank 2,
P2097 Post Catalyst Fuel Trim System Too Rich

So after that, I drove a bit more, and it started acting up. At low rpms (500-3000) it would kinda bog down and stumble I guess, at random times and it would last a few seconds... And just recently it has been doing it a lot more, for more than around 5 seconds, and at higher rpms, worse.

So now.. i replaced the spark plugs today, they were pretty damn black. CEL came on again after a few minutes of driving, and now in the high rpms when i hit boost it will stutter and act like its running on like one god damn cyclinder, and the CEL will flash, so that's new..

Thought It could be the MAF so I cleaned that to no avail. Used a fuel injector cleaner. Thought it could've been bad gas but i've filled up a couple times. Spark plugs made it worse and I only drove for a bit so I couldn't tell if the previous problem was still going on, which is probably is, but now I have an additional problem. I need help.. the car has 19k miles.. It's like new. I'd really appreciate any help you guys can give me, thanks alot.

 

[MS3 GT]

take it to the dealer if u still under warranty!

 

[Khrysus]

No warranty. :[

 

[jri4]

what mods?

 

[Khrysus]

no mods :[

 

[jri4]

bad O2 sensor? Don't take my word--wait for someone more knowledgeable to chime in. They will be able to get it figured out.

 

[b e z]

Sounds like someone sold him a bad car. Sounds to me they modded it and had issues they couldnt get fixed so they sold it and now it is someone elses problem.

 

[MSMS3]

The car should have a five year or 60,000 mile power train warranty and longer if it is an emissions related issue. Why does OP think there is no warranty, unless the car was modded and then found to be modded at a dealership before being brought back to stock when purchased by OP?

While there are a number of possible causes for this series of CEL codes, a bad primary 02 sensor makes the most sense. But that is an expensive item - over $300 for the part. Should be easy for dealer to diagnose and should be covered under warrant unless the warranty has been voided due to prior modding.

 

[speed3 britz]

From what it sounds like, Bad O2 sensor. I ran into same issue with a ms6 I almost bought. Ended up being a bad O2... thats just my 2 cents

 

[Protegebuddy]

Flashing CEL usually means something is MAJORLY wrong with car, suck to hear

 

[Russm]

Sounds like the same issues I had, Bad O2 sensor, Russ Darrow Mazda will sell you a new one for $180, ask for Chris.

 

[skallen]

Any update on what the problem was?

 

[meicalnissyen]

how is there no warranty? Only 19k miles on it? What, did you buy a rebuilt title car?

O2 sensors would be what I'd check first. Followed by checking for any major exhaust leaks between the engine and turbo (i.e. exhaust manifold gaskets). Sounds like this car was modded prior to your owning it.

36K or 36 months

08>11 = 36 months