does SES light hurt performance??
Thread Starter
Joined: Sep 2004
Posts: 4,085
Likes: 77
From: Fort Myers Florida
does SES light hurt performance?? im putting on headers tomorrow and i was wondering since im planning on taking AIR off and running no rear 02 atleast until i get a tune, but i was wondering if it will hurt performance or if it will just be annoying to see the light??
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
SES Light = can hurt performance (or has the potential rather... there are several hundred codes though... so to say an SES affects performance is a bit broad)
An SES Light for REAR O2s = 0 effect on performance
SES for AIR/EGR = 0% on performance
Rear O2s are ONLY for emissions .... the FRONT O2s are what can affect performance (if they're missing or lazy)
So long as the ONLY SES lights you'll be setting are AIR, EGR, and REAR O2 sensors.... performance won't be decreased
An SES Light for REAR O2s = 0 effect on performance
SES for AIR/EGR = 0% on performance
Rear O2s are ONLY for emissions .... the FRONT O2s are what can affect performance (if they're missing or lazy)
So long as the ONLY SES lights you'll be setting are AIR, EGR, and REAR O2 sensors.... performance won't be decreased
The short answer is: NO, but the problem that set the DTC causing the SES lite to turn "ON" might. The post-cat O2s only report cat efficiency. The PCM wants to see the amplitude of the waveforms reduced when they are compared to the pre-cat 02 waveforms. If the waveform is not reduced enough or not at all the PCM ain't happy and sets one of its' many DTCs. That won't hurt performance, but if the PRE-cat 02 was missing or malfunctioned that WOULD hurt performance. The only problem comes in when you get an additional DTC that wants to set the SES when it is already set. You can't turn "ON" a lite that is already turned "ON". As long as driveability isn't affected it's no big deal, but if you see degraded performance you might suspect that you have two DTCs at the same time both of which are commanding the SES to go set.
I have been driving my car since the summer with the SES light on because of no AIR and no cats. Like the others have said, THIS will not decrease performance. I can't wait for my tune though to get that light off, even though I am used to it, just makes it look like a big POS to people that don't understand.
