Please help p2252

[Kimerm2003]

Got a code for bad o2 sensor changed o2 sensor then that code went away got code for p2252. I checked wiring I have no idea what problem is book says bad PCM/ECM I doubt that's problem since it just occurs after changing sensor. Sensor was aftermarket universal and all sensors are getting reading on scantool monitor within normal specs I am lost with this whole thing here...

[jasondhimself]

how is it running? I asked because I had problem like that in my old car (trailblazer) I know its not an eclipse, but I changed the O2 sensor and still got trouble codes and it ran worse after I did that. The PCM eventually gave me the right code of misfire cylinder 4, I had a bad coil pack also. I like I said I know its not an eclipse but hope this gives you somewhere else to look

[Clovisman]

Sounds like you have a stock exhaust setup still. The code you have is rare if not a first at this site. If all four sensors are reading normal then your pre-cats are more then likely good.

If you are having poor performance and bad gas mileage, the the third cat might be the problem. If his cat goes bad it will cause back pressure and heat build-up in the exhaust, causing the performance problems. So I'd check the thrid-cat first, if this is good, then it's you PCM/ECM.

If it is your PCM/ECM, then this will have to be changed by the dealer, they need to program and register those computers with a MUT III computer.

ECM/PCM are not cheap especially if you buy them from the dealership ($900), so you might want to buy your one and have the dealship install it for you.

http://www.partswebsite.com/courtesy...n=3&type=parts

[matrho2792]

I actually have the same code on my car too after doing headers and replacing my O2 sensor with a universal too. I've checked all my wiring as well and I had a shop check the code with their Snap on tool and it said Bank 1 Sensor 1 negative current flow. I think it may be a problem with the O2 sensors. What brand did you get?

[deprydation]

Something you guys have to make sure, is that those universal ones are the correct ones for the place you're putting it.

Upstream/Downstream

Unheated/Heated

Makes a difference.

Our cars use 4 Wire HEATED O2 sensors. The upstream and downstream make a huge difference too. As a matter of fact, the upstream won't even reach to the downstream spot, but the downstream one will reach your upstream spot but will have a load of extra wire chilling. It's cruicial that you get these in the correct spots and connected to the right connector on your car's wire harness. This could throw all kinds of funky codes.

Make sure your sensors are right, but other than that, if you're stock and you have some warranty time left, I would claim a warranty issue.

[FeaRlezZ]

if it is the o2 sensor then the upstreams are the ones the ecu mainly uses for regulation. downstream is pretty much just an emissions lvl sensor. so if u have performance problems it is most likely upstream . . no difference in performance or fuel consumption then it is most likely downstream. . . but take clavisman's advice

[matrho2792]

I know this is a huge thread revival but I am proud to say I have solved my O2 issue with the code P2252. I replaced both of my upstream O2 sensors with new factory ones from Rock Auto and the codes went away. So now I have the OBX headers with no codes. Best part, the two brand new O2 sensors were only $100 from them. Hope this helps anybody else that runs into the same problem.

[FeaRlezZ]

^ good to hear. i would always stay away from those universal sensors

[matrho2792]

Well I was assured they would work of course. When it came down to it, they weren't even the right ones. I'm gonna stay factory on anything I need to replace from now on. I stayed factory on the new plugs I'm going to install this week as well with the Outlaw spacers. Thanks for everyones help.