97 gt running rich

[LR97gt]

I'm having a problem with my car running rich. The exhaust fumes are horribly strong and I get a puff of smoke sometimes when I get on it, also when I'm driving my cars air/Fuel ratio usually runs in between 14.3 and 15.6, but when I am slowing down and the rpms are dropping the motor will start to bog and the air/Fuel ratio jumps up to 22.3 and stays there. I bought the car like this and can not figure it out. I thought it may have been the plugs or wires and changed them but it still does it. I have no check engine light either. The plugs were fouled out too when I changed them. Put new ones in and checked them a couple days later and they were the same way. If anyone could help me out I'd really appreciate it thanks.

 

[96blak54]

How do you know the air fuel ratio? Does the car have catalytic converters? Is it full length exhaust? Are the O2 sensors reading?

 

[LR97gt]

My bad I forgot to add that. No cats, aftermarket H pipe into mac pro mufflers dumped right under the rear seats and yes the o2s are reading. I have a air/Fuel guage mounted in the car.

 

[96blak54]

Dumps under the seat will do it for you their!

 

[LR97gt]

But I have never smelled another mustang run like this does. And also was is causing my motor to bog like that when the rpms are dropping? And my air/fuel ratio to jump at the same time

 

[96blak54]

Did you ever get it tuned after the pi swap? I know what your talking about. Fumes bad enough to bring tears out. Mine did the same before the tune. The computer thinks the compression is still stock. Any altering from stock parts will cause an imbalance in the computers parameters or ability to compensate. Normally not a big deal, but your build is extremely opposite from factory.

 

[LR97gt]

No I never got a tune for the car. I read uo on the pi swap and most of the things I read said you didn't have to get a tune. But if that's what it takes to get it running right I will do so. Now my question is, is where and what kind of tune do I get and what are the price ranges? Thanks for all the help you are giving me

 

[96blak54]

Computer flashed dyno tunes can be had for around $250. A handheld tuner dyno tune is north $500. Email tunes are around $100. Your best tune comes from the dyno although a lot of people have had goodluck with just an email tune.

 

[Orange 94]

Moved to the 2v section for now, nothing to do with z introduction

Welcome to the forum.

 

[Cpotts13]

My vote goes for the dyno tune.. email tunes are great and all but they can't do any real time monitoring to pinpoint the problem like a tuner can on a dyno.

 

[LR97gt]

Thanks guys

 

[96blak54]

My vote goes for the dyno tune.. email tunes are great and all but they can't do any real time monitoring to pinpoint the problem like a tuner can on a dyno.

Very true^

Cpotts13 nailed it. You dyno tuner can monitor all the sensors and let you know whats faulty. He will also turn off the egr which is a big plus for us power hungry folk

 

[mjhkarter]

I'm confused. you say the car is running rich, but you quote numbers that are normal or lean. Rich would be less than 14 on your guage. If you don't have cats,is it possible your engine isn't running closed loop? If not it will default to the standard fuel map which is on the rich side.

 

[LR97gt]

My bad. That is what I was told. I still need to get it fixed. If you know a way to fix it can you please inform me. When it gets down to stuff like this I have know clue what to do. I bought the car this way and I know it's not running the way it should.