barlow100

Fellow owner has lost all power, can only accelerate slowly to 30mph car dies above this speed and wont accelerate at all, starts missing. Also has rattle from under car that goes away at cruise. No problems at idle.

Have done search for symptoms but no joy.

O2 sensors gone bad and no signal to ECU....?

Not blowing smoke or anything unusual.

desired_speeds

your CAT(S) are bad.

barlow100

Greetings all,

tests show cats/o2 sensors appear fine but a host of codes posted.

P2007
B28 (pressure sensor)
P0303
P0305
P0301
P0300
p2050
P2051
P2052
P2056

Most of these relate to misfiring cylinders 1,3, and 5

Any ideas please ?

cahiil55k

Just be happy it's not cylinder 8! Misses could be due to poor spark. Have you checked the conditions of your plugs?

CharlyE500

whats the mileage ?

Hulk

Check plugs, coils and injectors and do a compression test on each cylinder

barlow100

Thanks for suggestions guys, car has 60k miles, changing out plugs, testing coils, ignition module and checking cats.
Will keep you posted.

Hulk

Please do a compression test before buying any parts

BlkE55K

I lost power in my E55 before, also had a check engine light and a notice to visit workshop. It was caused by my supercharger belt breaking. Have you checked that?

Hulk

Oops

barlow100

Belt is fine, car had extremely bad miss while attempting to accelerate. Seemed to drop into limp mode.

Hulk

Ya that's why, I said compression...btw did you clear the codes then try accelerating and see if it causes the CEL with the cylinder missses or is it at idle?

barlow100

Thanks for interest, this is a buddys car. Engine fine at idle, miss only under acceleration. I am waiting to hear about the compression tests.

BBBSS

Could be a dieing fuel pump/clogged filter.

Has enough pressure/volume to idle, but put it under a load and it calls for more fuel and doesn't get it = misfire. Check fuel pressure, also while under load/misfiring.


A rattle under the car would make me think cats though. You sure those aren't falling apart inside? Get it in the air and bang on the cats with your hand and listen for anything in there moving around. Could be clogging up the exhaust from coming apart. Also watch for any white/greyish debris coming from the exhaust.

SegrestEllenl

Thanks for suggestions guys

03'55AMG

Is it RPM related? I ask because if you keep the shift points low vs high and do an acceleration test, wouldnt it be very easy to see if it was fuel related? youd thinkif it was a fuel issue, then going to a lower rpm would allow you to faster? Just my newbie opinion, correct me if im wrong

barlow100

After checking out all the obvious faults they went back to the original thought (thanks Desired Speeds ) and found that the cats were fried.
You guys think prices are bad in the US, a stealership here wanted 13800 USD for the replacement cat set.
Can we do away with the rear pair and only replace the front pair , thereby having a straight pipe to the rear mufflers ?
Thanks for the ideas and help.
P.S.The plugs were bad also.

Firechaser

Sounds like a great excuse to delete the Cats all together! The plugs were most likely destroyed from the cats failing too.

Hulk

^^^^^^ get rid of them all

Toadster

I know in the US (I thought it was worldwide) - 8 years or 80k miles full replacement coverage of catalytic converters

you have 60k miles, it's the years i'm worried about

barlow100

Buddys car is an 03 and I doubt there would be any point in approaching the dealer here even though the car is NZ new.
We will speak with an exhaust specialist and look to doing away with them (cats) altogether as suggested.
He has a basic tune and regularly runs the car at the top end of the speed range so he may well see an improvement in performance.

barlow100

Can anyone assist with o2 sensors and aftermarket cats ??

Planning to replace the front cats with aftermarket EUROCAT supposedly designed for European cars and delete the secondary pair altogether.

Will this aftermarket CAT cause any code issues if we keep both sets of O2 sensors. ?

Is a cross pipe or X pipe necessary to replace secondary cats ?

Thanks for the help so far.

Denroll

I would have asked the parts guy how he could quote me that with a straight face.

I'll sell you my cats for $8k.

barlow100

Thats why I buy my bits in the USA.