[rusty88]

Have a 95 GT. Just had a new H pipe put on w/ 2 cats. Since then my Check engine light comes on and car has hesitation on acceleration. The hestitation goes away after a while but the check engine light stays on.
Haven't checked the error codes yet, any ideas?
Thanks

[bsintzel]

Better pull the DTC on this one. I suspect fuel/air ratio is not being regulated correctly from the PCM.

[rusty88]

what is the DTC?

[Mr coupe]

Diagnostic Trouble Code...check to see if your computer stored any error codes

[90GT AOD]

Check to make sure both O2 sensors are properly connected, and it's possible that if you used your old O2 sensors, one of them got damaged when they were re-installed.

If they're both connected then check for codes.

[rusty88]

Thanks, will do. I didn't put the new H pipe on, had a shop do it. I figure it's something related to the exaust system, like the O2 sensors, EGR..concidering this all started 5 min after I left the shop.

[90GT AOD]

Sounds more and more like th O2 sensors, let us know what you find.

[crazyjag]

Might want to look into getting MIL Eliminators. They plug in between the O2sensors and the harness going to the ECM and should clear you MIL light. You can get them at most major mustang part suppliers. I bought mine from Racer Walsh in Jacksonville, ran me about $70, think Mustangs Unlimited is about the same.

[90GT AOD]

Originally Posted by crazyjag

Might want to look into getting MIL Eliminators. They plug in between the O2sensors and the harness going to the ECM and should clear you MIL light. You can get them at most major mustang part suppliers. I bought mine from Racer Walsh in Jacksonville, ran me about $70, think Mustangs Unlimited is about the same.

Why bother doing that, he had new cats installed.

[rusty88]

Originally Posted by 90GT AOD

Sounds more and more like th O2 sensors, let us know what you find.

Read the codes and came up with #172 "Heated Oxygen Sensor indicates lean condition right side" What would cause this?... bad O2 sensor?
Thanks

[GTS5.0]

I would replace both sensors. You don't need MIL eliminators, well they won't work on the 95 50's there isn't a second set of o2 sensors. The whole reason for having MIL Eliminators is because there is two sets of o2 sensors on 4.6 cars. They monitor both the cats. When you take the rear cats out of a 4.6 car the computer "sees" that and thinks something is wrong.

[rusty88]

Originally Posted by GTS5.0

I would replace both sensors. You don't need MIL eliminators, well they won't work on the 95 50's there isn't a second set of o2 sensors. The whole reason for having MIL Eliminators is because there is two sets of o2 sensors on 4.6 cars. They monitor both the cats. When you take the rear cats out of a 4.6 car the computer "sees" that and thinks something is wrong.

Thanks, that's the plan...change the O2 sensors. Wondering if I have a small leak where the manifold meets the H pipe if that would cause any problems with the sensor? The guy who put the H pipe on was afraid to tighten the bolts too much beacause the maniflod bracket is kind of rusted. Can smell exhaust in the car...not good also hear a thwaping sound coming from the general area. It's going back to him next week.

[90GT AOD]

Originally Posted by rusty88

Wondering if I have a small leak where the manifold meets the H pipe if that would cause any problems with the sensor?

That could be your problem right there, a exhaust leak at that connection could cause you to throw a code, because raw air is being drawn in.

[rusty88]

Got the car back. No more hesitation, check eng light or exhaust smell. Says he tightned up the h-pipe/mani connection and changed the O2 sensors. Running great so far. Thanks for your input.