So i have the P0420 code (low catalytic converter efficiency). It's covered under warranty, but my question is: Is it worth it to void the warranty by putting in a high flow cat? and is the HP gains worth it? if so, how much is the high flow cat, and what brand should i get?

 

Usually thats a code that gets thrown also when a oxygen sensor goes bad as well. What year and how many miles are on the car? usually o2's should be done every 60,000 miles

 

not worth it. if you didn't know, the cat is in the header or exhaust manifold. so you would have to take gut your stock header and put one in. the gain? probably next to nothing.

also, how do you know the cat is really bad? i'd reset the ecu to see if it comes back or not.

oh, and i dyno'ed my car after putting 3 inch exhaust on thus removing the secondary cat, and gained...3 whp!!! yeah, not worth it.

 

my car has 60,200 miles on it.....maybe its the 02...is the o2 sensor covered under warranty as well? i think there's like a $90 diagnosis fee??

 

I don't think that the sensor would be covered, but if the car is under warranty take it in and let them look at it and see whats up with it.

 

so from what's been posted, apparently you have no mods then all of sudden you threw a code? also, a cat would only decrease your HP even if it's a hi-flo cat, it still restricts some flow.

 

the only mod i have engine-wise is a cold air intake....but i've had that for a year with no problems

 

just reset it by disconnecting the battery, if the CEL comes back on, just go to an autozone or pep boys, they'll pull the code for free, and if it is the same code, then yes, you need a new car.

also, if you don't have a cat, your car's exhaust would smell bad, when i didn't have any cats, my car stunk something fierce!

 

o2 sensors are a wear and tear item....it might get covered if it was under 35000 miles but after not gonna happen.they are spendy to replace and the $90 fee to diagnose would almost get you anew one.

First check your sensor to se if it is loose,check the stock header to see if it is loose,check to see if your PCV valve is loose.....as that will throw the same code for it.....our buddy just got that and after all the removing exhaust and changing o2 and cats he found the PCV loose,tightend and restet the battery and it has ot come back with all the old parts on again.