well this morning i went and took my cat off....and lets just say it sucks..it is deff slower with the cat off i tested it before and after racing my buddy in his srt-4..i have cai and exhaust...he has spring mod...3inch exhaust no cat...mopar bov...big fmic... and he pulls me just a hair from a 40 roll till 100 ...k well i go and get the cat taken off because im putting my 2.8 pulley on today and then we raced after..well he pulled me about a car and a half after the cat was taken off....k so i thought well i lost some tq and ill make it back with 5psi more boost...so we put the pulley on and some ngk brk7e plugs [ 1 step colder] and then i go for a test drive to test everything ..well it is all fine and working and we go to race so see the result and and it was the same as with no cat...pulled me about 1 1/2 cars...so im thinking the car is not likeing the check eng light being on and went into limp mode..because this does not make sense it should be faster...im no stranger to boost i have had well over 8 turboed cars that were all pretty fast when i got done playing with them..so 5psi is night and day on most fi car...why not this one...this IS my first blower car so i am trying to get used to it.so im going to put the cat on my next day off and see if that helps also i will put my areoforce gauge on tomorrow and see if im getting and kr..i only run 93 oct gas...so im confused here share your input and let me hear what you think......

 

the stock cats flow pretty well... you have most of your restriction before the cat at the headers... i dont think you notice ANY difference by just removing the cat on the stock exhaust system

 

Dont ever remove your CAT! You will only gain top end! Deleteing the cat always makes you lose bottom end, plus you will throw a CEL and void your emissions warranty. Was your CEL from the CAI, or the CAT?

 

never got a cel on the intake....just taking the cat off

 

This is real easy to explain, you were already LEAN from no injectors, you remove the cat, better flow, now you are even LEANER which will melt your pistons!

 

GotBoost? - Hrmmm throw an cel, and void emmisions boo hoo, losing power? When I took off both cats in my Camaro and replaced with 3" straight pipe, if anything I gained I could roast the tires off all day long from a start 1st through 2nd, and there is a little things called 02 sims which get rid of that nasty CEL any one know if theres any made for us yet? And the only reason you really lose to the low end is because of the back pressure, so if your really concerned you can through a glasspack in place of the cat.

 

Did you do the boost by-pass mod to get the extra 5lbs of boost?

 

well i tryed the boost bypass mod and it seems to do nothing even without the mod the boost on the stock gauge goes to 15psi...and when i do the mods still stays the same and does not feel any faster...i ordered the aeroforce gauge yesterday from INTENSE MOTORSPORTS yesterday and had it overnighted should get it anytime so i can see if im getting kr or not....i need to order the maf trans and injectors from intense so i can tune it ....im sure it will pull pretty good then.....

 

YOUR CAR isnt ready for smaller pully anbd more air the car is designed to run at optium performance at the set up it is at now... changing a pully isnt going to do much unless u get an ECU reflash...... the biggest horse power gain is from ECU reprograming...... bolt ons arnt everything anymore computers pretty much run your car now a days......