JQuala

My car has been plagued with weird issues for a while like eurocharged tune not making any power and only making 415whp with full bolt obd and tune. My car has rotten egg smell at WOT and I start losing power around 4500rpm. My issues have been discussed in another thread I'll link later but wii an obII app I discovered this...my question is with this knowledge I'm taking my car to an Indy shop tomorrow what should I be checking? Vaccum leak, intake manifold leak? Bad fuel pump? It's a too new though to have a bad pump right? 30k My c63 notice my long term and short term fuel trims and fuel rail pressure...I thought the app was just inaccurate so...
I tired it with my moms E350 and what do you know regular fuel trim readings but discovered that her FRP psi was way higher.

roadkillrob

well 2000 psi is direct injection fuel rail pressure and 56 is non direct injection type fuel pressure, you can't compare them.

Our cars run around 60-65 psi give or take a bit and you would get a code if you were getting low fuel pressure.

AMGonFire

I can tell you this. I had an intake manifold gasket leak that I just had fixed. I don't know if it's your problem but it's an easy check. For me I had low trap speeds and a lower then expected dyno. Just had it fixed yesterday and it literally feels like I tuned the car all over again. The power I gained from the gasket fix is insane. I did not have a check engine light either. However had stored codes for misfire. Spray some brake cleaner where the manifold meets the motor. Worth a try.

Celicasaur

Interesting.

Mine is consistently at 51-53psi.

roadkillrob

That is fine, 60-65 is mercedes spec I think without motor running as most are in the 50's running.

Celicasaur

Ahhhh, thanks for confirming

roadkillrob

I looked it up spec is 4.6 bar running @1500 rpm, 50's ar idle is normal, should be mid 60's at 1500 rpm.

afguy0127

This right here is usually indicative of faulty catalytic converters. I'd have those looked at as well.

JQuala

i found this thread unfortuneately no resolution but plagued by kleemann headers https://mbworld.org/forums/c63-amg-w204/565380-headers-dyno-where-my-top-end.html

krazzdav

Just going from what you described and explained, you have bad cats. You can disconnect them and retest to see if your issue goes away.

ChatWithaNinja

This probably isn't your problem, but I did have a turbo Volvo back in the day that would only lose power at WOT at 4500 RPM. No one could figure it out and I finally did myself on accident... The air filter was broken and when the engine started to suck in the air at WOT it would get sucked in and cover the airbox opening to the throttle body. If you took the air filter off it would look just fine because it would snap back into place when at rest! I only noticed it when I was cleaning the air sensor and the filter bent too easy when I removed it.
I've never seen that before and I'll probably never see it again, but it happened that once, so I'm spreading the info.

shardul

iTrader: (1)

The LTFT are very high at 40%. This should trigger a CEL

roadtalontsi

JQuala

One of my afe filters are kinda squished on the side but don't think they are going anywhere the way our airboxes smashes them I place. Ty though

JQuala

I agree I used dash command and torque one on iOS and the other on an android tablet...they have come down to 25% but never ever gotten a pending or stored code. No cel except for P0101 maf sensor code that came on for a second but I got row air boxes with new mafs

Merc63

Long term fuel trim is out of whack. How's your plugs look? When has the o2 sensors ever been replaced?

I'd be talking to your tuner and asking why your long term fuel trim is so high.