Could the CAI be the culprit that causes rich A/F mixture in our engines? that possibily leads to Cat failure(meltdown)???

Thanks

 

Well when I had my Cai I was running lean on both Bank1 & Bank2 O2 sensors... I was running a stock cat. Since then I've switched to a PR Cai Upper Tube/JWT combo with the addition of a RT Cat...

 

Did the switch change your lean condition?

 

Yes it did.. Since then I've switched over it's been running normal..

 

So you didn't change any O2 sensors rite?

Thanks

 

PCGuru

How did you know it was running lean? Did you check it with the OBDII or did you take it to the dealer?

Only reason I ask is because I just bought me a PRCAI and will be installing it this weekend. BTW, I dont have a Cat, got a straight pipe and also got a Cattmany SS Ypipe.

Dixit

 

I knew I was running lean because I took it to a shop and they used a scanner tool to diag my ecu error code.. Nope, I didn't replace and O2's...

 

i have the CAI and an A/F ratio gauge, im never running lean and run rich on WOT

 

I know I'm going to get FLAMED for this one, but what the hell.


It's the Y-pipe. If you remove the precats you allow the heat build up/cooling effect to move downstream to the main cat, which causes it to overheat and thus fail.

This is NOT a 100% guarantee, but it does happen.

I plan on going with Dixit's straight pipe BEFORE I get my Y-pipe installed, therefore eliminating the chance of having to replace that EXPENSIVE pos.

Flame away!

 

Wouldn't getting a high-flow cat help to fix this?

 

... but you were at idle when they ran they pulled the code, right? Or did they take your car to redline with the scan tool still connected?

 

The RT high-flow cats SEEM able to handle it, but WHY spend $200+ vs. $50-70 on something that's NOT going to make you pass an emissions test anyways.

I don't understand why people think adding a RT cat is worth the money.

I argue that until you have at least a Y-pipe and catback FIRST you won't gain ENOUGH from an aftermarket cat to justify the cost and that the minimal gain is NOT noticeable. Peple have reported noticeable gains, but it's argueable that it's in their head. I too have added mods and the car feels faster, when actually it's that your just paying more attention, driving harder than normal, or it's just the added sound effects. Once you add a SC/turbo/NOS, you can see some noticeable/measureable gains.

Again, why not just spend $70 on a straight pipe to replace the cat vs. $200+ for a RT Cat? Performance wise there would be minimal difference, if not better performance from the straight pipe.

 

Wouldn't straight pipe trigger SEL on cars that have sensor behind the main Cat(Fed Emission)????

How do you solve this?

 

I don't think so. Nobody has done a Y-pipe and straight pipe?

If it does trigger a MIL(SEL), then it is possible to trick the rear 02 sensor(s). You just have to make it read a difference, either by putting a shield around it or possibly by adding a resistor to the wires. Not sure, but it can easily be done.

The rear 02 sensor(s) are ONLY used for monitoring cat or upstream 02 sensor failures by measuring a LARGE difference, so there isn't any ECU calculations to worry about messing up.

I'll look into it a little more. Maybe that's why people pay out for the RT cat. If so, that's a VERY expensive solution to a simple problem. Hmmmmmmmmm.