hey everyone well i bout a high-flow vibrant Cat. for my 97 manual civic HX (D16Y5).

so when i installed my header and Cat. and when i went to take it for a test drive my car started to act weird. when im cruising my car it starts to slow down like if i'm stepping on the brakes and letting it go and then stepping on the brakes again. so I decided to remove the Cat. and test drive the car with open headers to see if it will still do it and it didn't it was driving fine, i was able to cruise the car with no problems.

Now when i call the guys that sold me the cat. they said that my car needs to relearn it's self because it has a high flow Cat. or i can get it tune. I never anything like that

Anyone know what could be wrong???

 

wow...i put headers and a high flow cat in my civic when i had it and it ran fine or even better than it did. I never heard of a problem like that.

 

now i got a cel #61 which is the primary O2 sensor but i not surprise because there's a wire that's expose and i think it's causing a short and theirs no way i can fix that because it's to close to the sensor

 

it could also be your high flow cat. When the cat starts to break down it causes a block in your air flow and the enginge runs like crap hence getting the breaking feeling this is what happened to my honda when my cat went bad. I would have the cat checked and make sure the guys who sold it to you aren't getting on over on you. Tuning for a cat is stupid. The only thing that needs to happen is the car needs to be driven about 50 miles for the ECU to refigure itself. But still that wouldn't cause the braking affect. My bet is you got a bad cat.

 

Two solutions:

1.Reinstall your stock cat. Unless you're running FI or have a heavily built NA motor, that high flow cat does nothing other then giving you CEL and a loud exhaust note.

2.Get a o2 sensor simulator to rid of the CEL and reset the ECU.