CEL p1148
 

Unfortunately, I am stuck with a Performance's Shop mistake.

Read More here : https://www.myg37.com/forums/northea...ml#post3163382

They replaced my Stock cats with aftermarket performance ones and managed to break what I believe is the Air fuel ratio sensor 1.

From the service manual:

P1148, P1168 CLOSED LOOP CONTROL

P1148

Trouble diagnosis name
Closed loop control function (bank 1)

DTC detecting condition
The closed loop control function for bank 1 does not operate even when vehicle is driving in the specified condition.

Possible cause
Harness or connectors (The A/F sensor 1 circuit is open or shorted.)
• A/F sensor 1
• A/F sensor 1 heater

Can someone chime in and tell me what this means? From the looks of it my Air fuel ratio sensor (bank 1) needs to replaced? Is this the Air fuel ratio sensor that is located on the passengers side header?

How easy is it to replace this sensor? Can I DIY?

Thanks

I'm not entirely familiar with the bank part of your post. I was under the impression that our cars only came with 2 total O2 sensors. Is there a before O2 sensor as well? If you're talking about the one that I think you're talking about, then the entire process is no sweat. If I do remember correctly though, O2 sensors for our cars in particular aren't cheap. The O2 sensor's are plugged right into your cats. If it's toast for sure, then pull it out and toss it. If you think it's still good, just pull it out (w/ O2 socket) and place it into a plastic bag. Make sure you're NOT touching the sensor with your hands, etc. Be very careful. They're not extremely sensitive, but some (stupid) people say that mishandling it can damage it, easily. When and if you purchase a new O2 sensor, take it out and place it also into a plastic baggy in between installing; do not touch the sensor.

Jack up car, throw in jack stands, slide under, turn left to loosen, unplug the sensor (it's clipped to the transmission) and reverse to install. No biggie. GL! :)

Wait a minute...the header? Do we have O2 sensors prior? If they didn't touch your headers, in which they absolutely should not have (engine bay or directly off the manifold), then your initial O2 sensors should be fine. Adding high flow cats or even test pipes will not (100% sure) influence the performance of your O2 sensors pre-hfcs or tps. Like I said, it has to be one of the O2 sensors off the hfcs or tps that you had installed. If that's not the case, your car could just be throwing a code. There could possibly be a crack, or a leak. Both will throw codes - too much air flow (even the extra bit from a crack or leak) will cause your O2 sensor to read high, and therefore throw a code. Check for leaks (they HAVE TO USE silicon gasket maker in between the connection points of the headers and your new hfcs/tps; if they didn't, then that's your problem - you have a leak), and/or connection issues. Look for exhaust marks (stains) under your car - tells you leak points. You might also be able to hear it (aside from the slight rasp associated with hfcs/tps). Let us know!

Thanks for your feedback eksigned.

I believe my reader is showing the sensors that are connected to the headers. They are called Air fuel sensors. They are before the O2 sensors from the cat. I've read that they are known to get damaged if you are installing new rtp's/hfc's. The mechanic did use a new gasket and applied some sort of lubrication on the flanges.

The car does sound different and I don't know exactly how its suppose to sound like because I'm the first one with my set-up and I've never ran RTP's before.

I'll check for leaks but I'm pretty sure the air fuel sensor is shot... Hopefully someone can chime in if they had a similar experience...

i've been throwing a code since day one of my test pipes.... it's gonna happen unless you get non-foulers

Let me get back to you OMG35S. I'm pretty sure that, even with RTPs, there should zero influence on the air fuel sensors. It looks like just like an O2 sensor, right? Give me a bit to peak under my hood.

The A/F sensor which looks identical to the O2 sensor just a bit smaller is located above the top bolt. It is believed and mentioned by BERK that if you hammer and impact the top bolt the sensor can go bad. My code reader directly points to that sensor.

The sensor is easily seen through the engine bay without removing anything. Look at the headers on the passenger side and you'll see the sensor down below.

My RTP's come with an extended O2 Bung which should eliminate all CELs.

I'm trying to work it out. We'll see what happens.