Will a removed cat or bad o2 sensor decrease low end torque

[FlaminWhite97GTP]

Hello

I had a question about exhaust. It seems like my 1997 GTP pull very strong after 2500 rpm, but it seem like it will barely screech the tires in the low end. I was wondering because the catalytic converter was removed, will it have a negative effect on low end torque. I also have a SES light on because a bad o2 sensor, could that also be a problem.

 

[OH4CompG]

I know on an N/A setup if you lose back pressure you lose torque but gain hp. If your O2 sensor is bad it could be giving the PCM wrong info and getting your fueling all whacked out.

 

[blowfishRus6]

with a bad o2 its gonna run real rich. taking out my cat i did lose a tad lowend. but the headers made up for that i dont boost as high in lower rpm's but it still moves out better.

 

[FlaminWhite97GTP]

Ok just found out that the cat was replaced with a huge pipe (well it look like a glass pack, its about 4 inches in diameter) but it is huge & it's rusted. Could this be the culprit

 

[blowfishRus6]

back pressure is needed some times.

really tho, the stall in the auto should jump the car up to 3k~ so you should not see much rpms below 2500.

if you had a tuner you could up the timing in the midrange to help out with this.

 

[FlaminWhite97GTP]

Ok just got a new cataytic converter put on & it seem like I have all my low end power back (I can now spin the tires). Turns out the guy lied about stuff. I had no o2 sensor in behind the catalytic converter & I was running a resonator in place of the cataytic converter (so I had 2 resonators). I am now getting an average of 20.2 mpg in city (17.2 mpg before), this is when I am not punching it XD & I am still getting 32 mpg on the highway. So all I need to do is replace the 2nd o2 sensor & I will have no SES light.

 

[blowfishRus6]

my car cant spin tires either when its runing ober rich.

you might wanna reset the computer if you havent to relearn fuel trims with the o2 sensor back in.