SES & X-Pipe!? - The Unofficial BMW M5 Messageboard (m5board.com)

2003 M5!!! · 17th February 2003, 05:28

My SES light came on a day after having my x-pipe installed at Evosport. I take it from reading the various posts on this board that this is not unusual. . . ?

Did "we" ever come to a conclusion on what causes this. My general sense from reading on this topic is that either the x-pipe connection has a leak or that the set up is just letting too much air through. I guess if it is the later one, there is nothing you can do . . . ?

Can this hurt the cats? If so, why?

BostonRocket · 17th February 2003, 05:34

According to my BMW techs, it's the exhaust gases that are dlowing too freely accross the O2 sensors.

I had all sorts of random fault codes though. Faulty pressure release valve, loose gas cap, running rich in cylinders 6 and 8, running lean in 6 and 8 at idle.

For the most part, it didnt' take away any HP from me. In fact it probabyl added some hp. I kept the x-pipe on.

'Rocket

2003 M5!!! · 17th February 2003, 05:47

Thanks.

I take it there is no real risk of hurting anything (if I can live with the codes . . .)?

XrayMD · 17th February 2003, 06:49

I've heard of this as well. Fortunately, I didn't have this happen after installing my SS with x-pipe. I also have a code scanner that can reset the SES light so I don't have to go to the dealer (2 hours away!) every time it comes on. I wonder why this happens on some but not others?

17th February 2003, 07:16

XrayMD, where can I also get a code scanner?

Cheers.

BostonRocket · 17th February 2003, 08:06

I think you can get a code scanner from www.obdII.com. There was one unit that a boardmember posted which allowed you to clear the code as well.

My SES light went on when I was either:

1) Driving the car hard
2) Let the car sit at idle for a long time.

'Rocket

D/FW M5 · 17th February 2003, 15:01

I wonder if this phenomena comes from ecu learning, and once you change something like adding an x-pipe the ecu is now seeing out of tolerance readings coming from the oxygen sensors and therefore trigger SES. If this is true, I wonder if disconnecting the battery for a few minutes would clear the ecu so that it then has a chance to relearn with the new part from the get go. I think this can also work if you plan to dyno your car and have not been driving hard, resetting the ecu thru a battery disconnect may bring back some HP.

Doug

TriflowM5+M3 · 17th February 2003, 15:15

Well I take that back...i have had lights but they were lights due to a bad gas tank pump sensor and a bad gas tank pump. Something like that. I still to this day have not had a "bad" SES light...

Ill give credit because i unhooked the battery....im still sticking with that!

XrayMD · 17th February 2003, 16:18

I bought my scanner from HERE! , but there are a lot of others out there, including ones that hook up to your laptop or PDA.