CEL Light on with new hyper flow cats!!

Give it some time and the ECU might get used to them and eventually accept them. To determine if the issue is from the post O2 Sensor take it for a very spirited drive, ideally a high performance track session. If the CEL light goes out then it is due to the post O2 Sensor thinking your Cats are not working because they are so efficient. I have purchased O2 Extenders which place the O2 Sensor further out of the path of the Cat which is supposed to cure this. Since I do take my car to the track once and a while and the CEL clears itself I am not too concerned and am too lazy to put the O2 Extenders on during the summer driving season.

 

Usually extenders by themselves won't work. Extenders plus mini-cats O2 Simulator Mini Cat Cel Fix best oxygen sensor simulator made.

That fixed my CEL with Fabspeed cats.

 

Plenty of reports that the big daddies mini cats don't work either. I've got extenders to go with my de-cat pipes and don't really expect them to work. But my F-shop says no big deal we can sort it if it happens. If it happens I will hopefully report back with a fix. But they were not concerned.

 

I'll let you know what my mechanic does. He's installing new headers from Fabspeed and new cats from Hyperflo. He said something about also buying the "cheater" parts that will eliminate the CEL issue, because he knows I absolutely HATE the CEL.

EDIT: Here's what my mechanic said he's doing for my car:
Normal installation and proper tuning there 'should' not be any CEL but once in a while there is..to virtually eliminate the CEL (for catalyst reasons ) we install extenders which go on the front probe on the cat system..cats work because of variance of what goes in and what goes out..the extenders (cheaters) simulate more variance and insure no light..

 

Extenders by themselves won't work. Bigdaddies by themselves won't work.

Need them both.

Highly doubt that changing headers and cats are not going to trigger a CEL. Proper tuning? What does that have to do with an emissions CEL?

 

While I can't comment on the technicalities of the discussion, I'll be happy to report on any changes of condition after I have my car back, and have a few miles on the new system.