High RPM Misfire Solved!!!
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
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no,on a properly maintained engine that does not have a defective cat or cats and no fuel or oil issues the cats can last for a long long time.Don't ignore check engine lights.Don't top off your fuel tank.Replace o2 sensors at 100000miles.
In reply to some post above if your engine feels like it is being choaked and you get the p030* misfire codes on one bank of cylinders check the cat function on that side by measuring the pre cat temp with an infrared temp gun and comparing it to the post cat temp properly function cats will be hotter post cat and equal or close to equal pre and post on both banks.
Bank1 is passenger side bank 2 is drivers side.
Stock system and under 8years or 80000 miles which ever comes first and you have no worries.Dealer freebie
ohlord
"GOT CODES?"
In reply to some post above if your engine feels like it is being choaked and you get the p030* misfire codes on one bank of cylinders check the cat function on that side by measuring the pre cat temp with an infrared temp gun and comparing it to the post cat temp properly function cats will be hotter post cat and equal or close to equal pre and post on both banks.
Bank1 is passenger side bank 2 is drivers side.
Stock system and under 8years or 80000 miles which ever comes first and you have no worries.Dealer freebie
ohlord
"GOT CODES?"
Last edited by ohlord; Jun 23, 2008 at 04:53 PM.
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CLS55 Designo 030
Thanks for the suggestion ohlord.
I just did the delta T test you described above but since the cats are so close to the engine/headers I could see why the higher temperature reading pre cat. No conclusions on a cat malfunction there.
I'm going with the cold/hand test tomorrow. I basically put the car in a lift/rapm, grab the cat, and I check for rumbles or parts shaking, correct!?
I just did the delta T test you described above but since the cats are so close to the engine/headers I could see why the higher temperature reading pre cat. No conclusions on a cat malfunction there.
I'm going with the cold/hand test tomorrow. I basically put the car in a lift/rapm, grab the cat, and I check for rumbles or parts shaking, correct!?
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2002 C32 AMG
After that, I checked my cats and they looked just like the pictures Jerry posted.
Last edited by Eleventeen; Jun 23, 2008 at 06:06 PM.
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CLS55 Designo 030
I had the same issue and I tried that before checking the exhaust system, but to no avail. That's when I knew there was something more involved. The new MAP has a different P/N and was only $53 from the dealership. It is a little bit tough to get to, but if you remove the throttle body and driver's side plenum (manifold) and use an E8 torx with flixible 1/4" extension or universal joint, you should be able to do it without removing the S/C. It took me about an hour.
After that, I checked my cats and they looked just like the pictures Jerry posted.
After that, I checked my cats and they looked just like the pictures Jerry posted.
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2002 C32 AMG
I guess it's still possible that your MAP is bad, but if you are getting P0108 in conjunction with several misfire codes, it is probably blocked exhaust flow.
Last edited by Eleventeen; Jun 23, 2008 at 07:20 PM.
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I have 62,000 miles, but only about 1200 miles on the cats. They were Dynatech PowerCats. They had the same type of corrugated metal substrate as the Random Techs. They flowed well and sounded great until the insides collapsed. I don't think they were designed to be mounted that close to the engine. Plus the C32 has specific features meant to transmit more heat to the cats for faster light off (single exhaust valve and double walled manifolds). I might try going back to HF ceramic cats.
I guess it's still possible that your MAP is bad, but if you are getting P0108 in conjunction with several misfire codes, it is probably blocked exhaust flow.
I guess it's still possible that your MAP is bad, but if you are getting P0108 in conjunction with several misfire codes, it is probably blocked exhaust flow.
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CLS55 Designo 030
OK, here.
Jerry, Eleventeen - did you replace the O2 sensors?
I'm still figuring this out. I spent 30 minutes talking to the guys at Random Technologies and I'm trying to look for the obvious first...
Jerry, Eleventeen - did you replace the O2 sensors?
I'm still figuring this out. I spent 30 minutes talking to the guys at Random Technologies and I'm trying to look for the obvious first...
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From: Houston
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From: South Jersey
2002 C32 AMG
However, that will probably be the next thing to go.
