Sluggish after exhaust! Why?

[yomny]

I did some search but i really couldn't find anything on why the car feels asleep sometimes after i put the exhaust. The car is a 01 GT and it only has a ful exhaust with x pipe no cats and flowmasters ( 2.5" piping). Sometime si feel the car not as responsive as it used to be, another times it runs nice. I also smell gas from the exhaust, but it smells really strong every now and then. I know the smell coudl be due to the lack of the catalitycs but is it normal for it to be this strong. My car is completely stock besides the exhaust. So in conlcusion why does the car feel dumb sometimes. One more thing, what is modular, i hear about the modular 4.6 alot? Thanks for your help and tak einto consideration that im new to the mustang world, take it easy on me. Thanks for your help, in advance.

Regards
Yomny.

 

[Solid Snake]

Sounds like theres a leak somewhere

 

[Sam98]

Mine has that smell too, but I know that it isn't running too rich. Loss of low end torque is normal, because the back pressure helps at lower RPM. It may just take a little while for the PCM to re-learn how to keep the A/F right. Hopefully that's all it is...

 

[yomny]

hope is all that, i mean the car is basically new, i dont' think it should have any problems, now what is the PCM, and can i make it learn faster maybe by resetting the ECU, by disconnecting the battery or something. Thanks a lot

 

[el_kid_1]

It could be a leak. When I installed my LT headers, my car wanted to eat the pavement. One more thing, did you check your o2 sensors?

 

[70stangcoupe]

And to answer your other question... the 4.6 is called modular because there it is an OVERHEAD CAM motor, not in-block cam like most older-designed motors. The 4.6 doesn't utilize pushrods.

 

[yomny]

You mean exhaust leaks, i dont' think there are any, i was there when they intalled the exhaust, the guy made sure everything was really tied up, the 02's i should check the upper ones right,the secondary ones most likely will read lot of gas and throw the CEL soon since i removed the cats. But I'll check them to make sure they're all connected, thanks for all your help/info.

 

[03trubluGT]

It could be a leak. When I installed my LT headers, my car wanted to eat the pavement. One more thing, did you check your o2 sensors?

My car almost scared me after the new exhaust. The dyno showed that I gained almost 23 rwhp and 19 rwtq.

Matt