been trying to tackle down this error for some time. Initially, I was getting P0108 when going past 6500 rpm. Thought it is the MAP sensor on the intake manifold, replaced it - no luck. fixed few vacuum leak, cleaned air filter, replaced intercooler boots. Still P0108. read some more forum posts. Replaced the MAP sensor near the airbox. Still no luck. now , I can not even rev up past 5k rpm. engine is making some really weird rattle when the revs go past 4500 rpm, but until 4000 rpm car runs just fine with no issues at all

Car has around 120k miles. it has a 15% pulley and an RMW tune.



Any idea what else should I be looking at ? Thanks guys

 

Timing Chain/Rails/Tensioner, have you checked those?

 

No I haven't. What puzzles me is the normal functioning of the engine until I start flooring it past 4k rpm. If the chain comes loose, will the car run fine under 4000 rpm ?

Thanks for the reply! I appreciate it

 

Hi Guys, I checked connectivity from the TMAP and MAP sensor going all the way back to the ECU connector on the wiring harness , voltage from the TMAP sensor live data while driving. The sensors work perfectly there is no short etc. It's just that the boost is too much so the TMAP sensor is sending high voltage.



With that, it's my assumption that the cat is clogged causing the back pressure. I don't hear the usual pop and burble from the exhaust at all. This supports my conclusion of cat being clogged. I am pretty sure the stupid foam filter oil must have caused it.


Is there any way to clean the cat, other than taking it to a muffler shop ? Thanks

 

Hope this helps someone - a melted catalytic converter can give P0108


well, my assumption was right. I cut open the header right before the pre-cat and take a look at the picture

I end up getting a used header and the car is back to normal

 

Great thinking on your part. So it was the precat and not the cat.

Talk about a finger in the dike.

 

Another reason that I think oiled air filters are nothing but marketing hype. Yeah you get a little better air flow, but at the cost of problems such as yours and poorer air filtration. Personally I don't want to add a sandblaster to my engine.

 

Would think the question is whether the precat melted or just broke apart. I am thinking the precat is made differently than the cat so that it can handle emissions while the engine temperature is lower. The Toyota MR2 had allot issues with the precat.

On the matter of oil air filters, how can that lead to the precat going?

 

By clogging them up with burnt oil residue. My header separated just after the pre-cat which is a common problem on R53's. I pulled it and welded it back together. The pre-cat looked perfect after 104k miles. My car has the updated JCW air filter. When I got the car I changed it. I would be willing to bet that it had never been changed before. Looked pretty dirty on the outside, but clean inside the cone.

Different application, but I put an oiled filter/cold air intake on my 06 Chevy truck. I get a CEL for the dirty MAF sensor that is right after the filter. I have to pull it and clean it often.

The cold air intake is a good idea, but MINI's already have that.
Show me a third party dyno test by someone who is not trying to sell you an oiled filter that shows an actual HP gain and I might change my mind.

 

Correct, only pre-cat melted. The secondary cat was just fine



It all started after I bought the Uni foam filter cleaning kit and followed their cleaning/oiling video . I am, not even putting that link here, so nobody get to see it and get into this mess. Video shows to spray a lot of oil liberally. Wrong! The video may be applicable to naturally aspirated engines, but not for forced induction.



my intercooler was full of oil, tmap senor was bathed in oil. after my pocket was $200 lighter with new MAP sensors and days of work inspecting everything under the hood, I took my chances and pulled the header out to inspect

 

Thanks I just spit milk out of my nose reading that.

The amount of oil in an large oiled air filter wouldn't amount to maybe an .5 ounce and that's if you laid in on super heavy.

The R53 runs higher than average EGT and with the raw fuel being dumped in on decel (this is what gives the pops and bangs everyone loves ) the life span of any cat is limited under hard use.

These higher than average temps are also what kill the expansion joint (aka flex joint) in the header.

It has absolutely nothing to do with oiled air filters.