Check engine light ON...

Today I am merging into a highway on a ON ramp slightly uphill and I gently punch the throttle pedal half way down to gain speed, but the car boggled down... lost power for a sec or two, and I let off the throttle and car continued to move but with slow acceleration and with a "check engine" light lid up in the panel. Drove about 15 miles at 70 mph no problem. Upon hitting traffic again, I noticed that if I am at a traffic light and light turns green to me, I can press on the throttle slightly and car moves fine but with a slow acceleration. If I depress throttle a little further and deeper, car hesitates....let it off...car maintains slow acceleration and moves ok. So, I think this has something to do with a Throttle position sensor....? push it down and hard forcing a downshift causes problems....steady on the throttle and all is "fine". what you fellows think this could be? also there is a very small trepidation while sitting still, in P. If I put it in N, trepidation goes away. Thanks for any insights folks.



ok, went in there....he said General misfire codes...1, 2, 3 and 5 cylinders....something like that.
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Possible causes:
- Faulty spark plug
- Clogged or faulty fuel injector
- Faulty ignition coil
- Fuel injector harness is open or shorted
- Fuel injector circuit poor electrical connection
- Ignition coil harness is open or shorted
- Ignition coil circuit poor electrical connection
- Insufficient cylinder compression
- Incorrect fuel pressure
- Intake air leak
MAF error codes are P0100, P0101, P0102.
I also have SDS on my laptop.
Why are you scared of getting second opinion? Is your mechanic the only one in the state? I doubt it.

Possible causes:
- Faulty spark plug
- Clogged or faulty fuel injector
- Faulty ignition coil
- Fuel injector harness is open or shorted
- Fuel injector circuit poor electrical connection
- Ignition coil harness is open or shorted
- Ignition coil circuit poor electrical connection
- Insufficient cylinder compression
- Incorrect fuel pressure
- Intake air leak
MAF error codes are P0100, P0101, P0102.
I also have SDS on my laptop.
Why are you scared of getting second opinion? Is your mechanic the only one in the state? I doubt it.
Obeone......I don't understand why is he insisting on the CAT being the culprit when you list several possible causes for these codes (they all make sense to me BTW), but you don't mention a bad CAT being one possible cause.....
when the car was on the lift, he used what appear to be a UV light to illuminate both cats and one definitely had a totally different "yellowish Glow" to it than the other.
when the car was on the lift, he used what appear to be a UV light to illuminate both cats and one definitely had a totally different "yellowish Glow" to it than the other.


now I am thougrouly confused. make a long story short. Shop did not know when new Cat would come in. I did not accept that. so I called the local MD dealer from whom, they order it. Ask the parts guy about the Cat order from that specific shop for a 2000 E55 amg. he looked for it, found it and said Cat is coming from Germany so 2 weeks minimum.
Ok, I figure I go get the car, and drive around (slowly) until they call saying Cat is in.
Drove it home, very gently. CEL still there. nothing wrong except "I've been told" to stay off the pedal. to not accelerate hard.
So, ...(you know whats coming right guys?.....lol) as I approach home, I thought...heck let me punch it see what happens....worst case scenario...I go limping to the garage 1/2 mile away. Punch it, gear dropped, car jumped and glued me to the back of the seat.........
Total confusion in my head.....I did it again....no issues.....
So.....here are my thoughts.
Nothing is wrong with the Cats
The misfire was isolated...caused by bad gas....or
it was a bad electrical short/bad contact in the left harness....or
isolated event somehow...
Nobody cleared the CEL.....but car drives 99% normal
I will fill tank and pour some STP injector cleaner or Lucas Injector cleaner and drive it (semi) hard....this is what we call in the FerrariChat site "an Italian tune up". Monday I will take it to another Guy in town for a second opinion.
Any thoughts fellows? Thanks a bunch for the help so far.

I'll share my experience, when I accidentally spilled Redbull onto my shifter (BTW our coffer holder design is awful) my car went right into limp mode and CEL. In addition my car would not change gears. Stayed in 1st gear actually. 10 miles turned into 30 min slooooowww ride home. When I got home I pulled the codes and I can't remember but I know there was a few. I ended up buying a used shifter from Ohlord one of the guru's in the W210. I'm just thinking what are the odds that your getting error codes and the car is driving fine? Coincidence? BTW- It's a 50/50 chance if you can save a TCM. Just depends on how fast you can get it cleaned and dry. I wouldn't be surprised if it still has Gremlins after the spill.
*Would be nice if you could test the theory and test?
Armani

https://mbworld.org/forums/e-class-w...ft-module.html

I am waiting for this heavy rain to subside before I take this fine machine out for a ride and see how the tranny responds.
I am still considering taking her to a second mechanic tomorrow first thing AM to get a second opinion, but I am strongly leaning towards NOT replacing the cat. For those of you whom asked me about the CAT cost, he quoted me $2,400 for one (!), and it is coming from MB AMG Germany, so I will put a stop on that. thanks.

All kidding aside guys, how can a car with a confirmed P0300/301/302/305 etc Misfire codes provided by a Star Diagnostics System (SDS), with an experienced mechanic pretty sure I have a bad Cat, CEL on, etc, etc......become this monster of acceleration after I disconnected the battery for almost 2 hours?
possible culprits in my mind...:
=batch of really bad gas (got new tank of fresh gas now, plus Lucas Injector cleaner shot
=Transmission "forgot" how I drive, and Battery re-set re-started from new
I depend on the forum's collective wisdom now....to figure this thing out......but ONE thing I now for sure.....under normal conditions and all systems working THIS CAR IS A ROCKET!! UNBELIEVABLE ACCELERATION!

Yes, I am glad car is better now. Still unsure of what cause the issue in the first place.
I am very interested in changing the headers, and then follow the example of others here, whom replaced the cats for 300 Cel high flow units, and replace secondary with X pipe, etc.
I need some ideas of where to start sourcing these components, while I search for a reputable shop in Houston to tackle the installation. Thanks.







