[gT-BMW]

hey guys just curious if anybody here with catless headers was able to eliminate 29F4 (P0420) - Catalyst System Effeciency Below Threshold (Bank 1)
29F5 (P0430) - Catalyst System Effeciency Below Threshold (Bank 2) without a custom tune?

[hassmaschine]

Why would you go through the expense and trouble of headers, but not get them tuned?

[NinetyEight740]

Originally Posted by hassmaschine

Why would you go through the expense and trouble of headers, but not get them tuned?

100 percent. Make your engine breathe better but not add the fuel to make more power. Completely counter productive.

[Savedamanualse90]

Buy a L shape defauler, best value for the buck..

[gT-BMW]

Originally Posted by hassmaschine

Why would you go through the expense and trouble of headers, but not get them tuned?

im selling the car and im trying to get rid of the cel

Originally Posted by NinetyEight740

100 percent. Make your engine breathe better but not add the fuel to make more power. Completely counter productive.

i might as well get milv then get a tune. counter productive to pay twice.

Originally Posted by Savedamanualse90

Buy a L shape defauler, best value for the buck..

did you mean this? if so anybody using these?
https://o2spacers.com/collections/o2...ytic-converter

[gT-BMW]

there doesnt seem to be alot of info on these L shape defoulers so i bought a set on ebay and just installed them. Omg what a pain in the ass it was to install!! So far so good no cel ����. Ill update in a few days if anything changes.

10/5/19 update. So the SES light came back on. But this time it took alot longer. It also came with extra codes 2c7c. dunno what that is some sort of signal code. 2ef5 thermostat. 2a17 dmtl pump. 2aa9 variable intake servo motor i also have low rpm hesitation. geez this is going to get very expensive but im on a mission to remove the SES from the dash. ill update again on these lil things after i fix everything.