Hello all,

I own a 2014 Mustang GT with the Boss 302 H-pipe, Roush axle back exhaust, and a Steeda CAI with a Brenspeed tune and I took her last week and today to get the state inspection done and it failed in two areas for the o2 sensors.

I've been reading around and have been talking to the guys at Brenspeed and was told that my o2 sensors were actually not turned off but are on in my tune, so I decided to reinstall the stock box and run the stock tune.

I drove the car around for a while and went back to the inspection station to rerun their test and it failed again on both the o2 sensors.

I decided to go to the stealership and ask them what was up and the service guy I spoke to told me that it is known with aftermarket exhausts to throw the o2 sensors off because of air flow. His recommendation was to install the stock midpipe and exhaust and redo the inspection.....welp I don't have those pieces any longer.

I was wondering if any of you guys have encountered this situation?

I don't know if this is a question allowed to be asked, but does anyone know any inspection stations that do not test for emissions in the dfw area? or any shops that would pass my vehicle?

Thanks for any input,
Jayson

 

Sorry I can't help, but if you don't get an answer here, try starting a new thread in the Tech section for your year Mustang. Just because there's alot more people in that section.

Good luck

 

Or you could just have defective O2 sensors, unusual, but not unheard of.

 

Are you getting any codes? Is it running lean?
It would seem strange that better flowing exhaust would through it off enough to fail. If it's running lean I'd check for vacuum leaks first. If it really is a lack of back pressure, you could try the old motorcycle trick-stuff steel wool in the exhaust pipe. You'll need a way to keep it in-like a # 8 bolt that passes through the exhaust pipe closer to the end of the pipe. Might also check your air cleaner to make sure it's ok.

 

God, what a nut roll.

No state inspections, ftw.

 

I guarantee the mufflers won't affect your 02 readings there's tons of people with no mufflers at all that pass everyday. I used to test for Georgia. Grab a scan tool and go to the I/M readiness page and see what monitors are incomplete. Also check for pending and set codes to help narrow it down. Did you use any 02 extensions? The cheap ones have been know to fry 02s they get hot and short out. Also how long did you drive on stock tune before testing? You have to complete the Ford drive cycle to get all the monitors to show ready.

 

She is not running lean and I am getting no codes.

The first inspection was done with the intake and tune 1000 miles post reset. I did the second inspection with the stock airbox and stock tune 50 miles post reset.

It says o2 sensor and o2 sensor htr in not ready status.

I did not mess with the o2 sensors at all.

This all makes zero sense.

Jayson

 

Are the o2 sensors still in the stock locations?

 

Yes. The only thing I have changed in this vehicle is the mid pipe, axle back and the intake.

 

if its failing both the heater and the sensor sou ds like something is unplugged. Check the connections on the sensors. Also if you have a multi meter you can test the resistance to rule out the sensor being an issue. I forget off the top of my head but there is a Google article that describes the readings you should get. But I'd start by unplugging and replugging the O2s. Also it can take more than 50 miles. You need some interstate and some city driving as well as no sudden acceleration. If driven some cars as much as 200 miles to get them ready. But if the problem was their with the aftermarket tune as well and they are sure the sensors are turned on then I'd say you have a sensor or a cat problem.