Have an issue with 2 engine codes ever since I installed header and catback fully catless. Thought that after the EVO flash the codes would be gone but it was not the case.
The car seems to be running fine but still would like to know what those codes are for:

P0431 & P0421

I have already contacted Ian and Todd at EVO but they informed that they have no info on those.

Any info will be greatly appreciated!

Jose

 

do a quick search on google...

Warm up catalyst below threshold seems to be message associated with the codes. The codes mean the same, just one code per bank.

Are you using premium gas? Try a different station to see if the code persists. You'll want to clear the code first.

How old are the cats?

May be your 02 sensors

If your plugs are old, replace them

 

Djantlive

Just checked the code through internet...
Appreciate your response. This car is a 2006 with 14,000 miles in it.Bought the car 6 months ago with 12,000 miles
The header and Remus cat are new as well as sparkplugs (replaced plugs 2 months ago already having the engine code as Header and Remus came in before).
Shell 93 octane. I will try the gas idea and see what happens...
On the O2 I was given an idea to restrict the sensor surface. (seems to be very common with other cars with similar issues.
The car is fully catless.

Thanks , Jose

 

As I understand it your sensors are reporting non-functioning cats. Since you have no cats this would be accurate. I don't know how to eliminate these CEL codes for a 987 track car with cat delete. ROW DME reflash perhaps?

For more info:
http://www.renntech.org/forums/index..._1#entry179855

 

Will follow that thread on renntech!

I have a "RS350" kit which included the ECU flash from EVO. I was assured that with it I would not have any problem with engine lights... yeah right!

I will most probably do the surface restriction on the sensors as it seems to do the "job" needed in many other types of cars running catless.

Thanks

Jose