OK, many of you know that I have been dealing with high RPM misfires for about a month now.

I have spent hours upon hours fighting with my car trying to figure out the issue.

I thought / said it was the cats from day one, but we checked all of the obvious stuff first.

Needless to say.......


I was RIGHT!!!


Car runs perfect again.....even though my cats are now gutted and a simulator is in their place.

Enjoy the pics!!






Big thanks to Fluid Motor Union (LET Partner) for helping me with countless hours of work. I really trust OJ & Lucci and value their work and opinions. I really hope that LET can bring them much business in the future!

If you're in the west burbs and need to have quality work done, call Fluid Motor Union. They are moving into a new shop as we speak with a brand new Dyno Dynamics dyno, customer cafe area with an internet workstation, wireless, big screen, etc.

The old shops address is:

Fluid MotorUnion
10119 South Mandel
Plainfield, IL 60585
Phone: (630) 946-0166

We now have 2 partner locations in Chicago to better serve you!

I'm glad your car is back to normal Jerry. Can you explain the symptons of what happened?

WOW those cats are restrictive, no wonder they failed.

amg-jerry, i'm having the same problem as you. my car is missing too. how do i check to see if it's my cats.

sweet.....you know the new address? They are right by us!

How in the world was the car even running???????

how did you determine it was indeed the cats? Backpressure test?

They started out as 100 cell racing cats by Random Technology. One of the best cats made...

[

We now have 2 partner locations in Chicago to better serve you![/QUOTE]


What are those partners???

glenn

The car drove perfectly until I hit 4800 RPM's, then it would do a random cylinder misfire.

The issue was caused because a catch can full of oil that wasn't monitored correctly and the vaccum lines sucked that oil back into the intake which made its way to the cats.

Well, is it missing at random or is a the same cylinders over and over?

Does the car drive fine until a specific RPM?

Can you provide more info?

Chicago Performance & Tuning in Melrose Park

Fluid Motor Union in Plainfield

I remember someone mentioned installing a catch can on our cars before. Do you think your problem stemmed from the catch can overfilling or not having one installed early enough?

It has to be from it filling up...I installed my catch can last year and have emptied it many of times.

No, I don't have the new address, but I have been over there and the new place is about a block away.

Did you have a P0105 code coming out?

Everytime the car misfired, I got that code. If it didn't misfire, I didn't get the code.

Great! That's exactly what is happening to my car. So, how do I tell between a bad and a good cat? Any available upgrades besides the OEM ones?

Thank you Jerry, you have made my day. I checked a few things with Erick and Sunil but we couldn't nail it down. My car has 110K miles and this is my first CEL.

So what is the net effect of all that oil going into our intake? Carbon buildup inside the engine/valves?

Does your car use 4 cats like other MB's and if so are you still running all 4? Also, what do mean by "cat simulator"?

If the PCV gunk made it all the way to mess up the cats I'm sure your top end could use a cleaning also. Just a thought.

Wow now she ready for the track again on July 19th.

Can you describe your issue in detail and what you have tried? Misfires could be many things....I don't want you to waste your time.

The only way to tell would be to take a look inside.....they drilled a small hole in front of mine and used a borescope to take a peek.


Here is what happens when the little rubber T fitting on the bottom of the throttle body fails...this was last year. A catch can would have prevented this.

http://www.renntechc32.com/oil/


No, I have a complete custom exhaust. I only had the 2 100 cell Random Tech cats. The car came with 4 cats, but I removed the second set and upgraded the primary set.

I'll find out what they put inside and I'll let you know.

We did replace the Supercharger and Intercooler. We also cleaned the intake ports and checked everything out.


I hope so...will let you know!

Jerry, it's me again We exchanged PM's about 8 times last week while you helped me diagnose the same problem. I didn't realize you were having the problem too. That is EXACTLY what my cats looked like. I pulled the exhaust pipes off when you mentioned a possible exhaust restriction. It looks like you have (had) the metal substrate cats as well. I guess these don't work on our cars with the high heat and exhaust pressures. Back to ceramic maybe?

Thanks again for helping me diagnose!

No problem! Not sure what I'm going to do now...

You guys don't have emissions inspections in IL, right? Might long-tube headers be in your future...?

My symptons are exactly what you originally described. I want to check a couple of things before going into the cats.

Have you replaced your MAP sensor before? That's the first thing that comes to mind.

I have had nothing but problems from Random Tech cats. I had them on several cars including my STI and the were garbage. The service at Random was horrible also.