uberwag

Hi all-
Wanted to put this out there to see if anyone has any bright ideas. Have a E55 wagon that has a Stage 3+ (just updated my build post here: https://mbworld.org/forums/w211-amg/...ld-thread.html ) and I'm trying to hunt down some pain in the *** check engine lights and a rough idle.

At idle, the car is giving me some problems. First off, whenever it is in idle, regardless of whether it is in P/N/D, the headlights/interior lights will dim/bounce with the RPM and stereo. The engine will occasionally stumble and the RPMs will bounce all over the place (between about 500-575, with some lower dips in there occasionally). Even when the car has a more steady idle, the lights are still bouncing all over the place. However, the volt ready on the dash is saying ~14v at idle, and at 2000rpm in neutral. Haven't check it while driving yet.

The codes that the car is throwing occasionally is P0505 and P2096. Sometimes it will throw P2096 by itself (did that today). I've been clearing them to see if there is a pattern, but nothing sticks out yet. O2 sensor in the faulting bank has been replaced, and now it says it is P2096 on the other bank. Ideas, all?

jcjmw

If you do a search for those codes, I believe sometimes those codes come from extending the O2 sensor to install LTH. Did you extend your O2 wires?

Denroll

Sounds like an issue with the 82mm throttle body or a gasket. I get it also, but only after driving it at part throttle for a while. When I come to a stop, it's a lumpy idle and my short-term fuel trim pegs out at like 25%. If I restart the car, it runs normally. Still molests others when I get on it, so it's just an annoyance.

CLKCLK

Valcum leaks? Exhaust leaks? I got P2096 due to an exhaust leak right at the collector. Fixed it and code is gone!
Gl

Lelix

For P2096 make sure your post O2 sensor plugs are not reversed. P0505 sounds like a vacuum leak.

uberwag

Thanks all. Don't think the O2 wires were extended, but worth checking out. O2 sensors not reserved (thank god..it would have gone through about 5 dyno runs and 3000 miles of being reserved if so ha).

My next step will be voltage regulator-easy and cheap enough with the great DIY on here, and would explain some symptoms. Will also reflash a tune from Jerry/Eurocharged to see if that will help.

CLKCLK

No one here has advised you a voltage regulator. Save your $, time and energy!

Gl

uberwag

CLKCLK- Got it on my build thread(see here), and from my MB shop in Orlando (FS Tuning). The cost was $50 shipped and there's a nice DIY on it, so gonna do it anyway. If nothing else, $50 to rule out an issue is worth it at this point.

loungn14

agreed... 505 is typically tb related... Try to do the tb reset and see if you still get it, then check for unmetered air as well as throttle percent at idle.