Just picked up an '05 Cooper S model...Im getting the p1498 code which is Fault code P1498 unmetered air after compressor. The common fix seems to be to replace the plastic inlet duct at the supercharger. According to a reciept found in the car, this was done last month. Another thing thats leading me to think its not that is there is no rough idle.

My symtoms are, obviously the CEL and the EML light on. When driving and constant speed, the car has a hesitation, seems to only be when its under vacuum. As soon as i press the go pedal and boost builds it runs great.

I have changed the plugs, wires, and the coil.

Any suggestions would be appreciated, ive been hunting for a loose or cracked hose of some sort for 2 days now. I also did the ECU reset today, CEL and EML light popped right back up....Help?

Keith

 

Noticed this morning that it DOES have a little rough idle....Think its possible that the shop that did the work didnt get the thing sealed right? Any easy way to check?

 

Nobody?

 

I own the exact car with a manual transmission. It has actually been sitting up for a year because of this issue. I have been scouring the internet for answers to my problem with the EML light at the P1498 code. Crazy enough, I read this post and see that you have the same car and issue.

My car will just stop accelerating just randomly while driving. I can put the pedal on the floor and it doesn't rev past a certain point. It's going into "limp mode" from what I've picked up. I have to throw it into neutral and restart the car. It happens quite often, making it a pain to drive. I read other forums with people with similar issues who replaced the crank and cam shaft sensors. I just replaced my crankshaft sensor today, didn't fix the issue. But now I'm getting a P3040 code which is a camshaft sensor problem. I read that replacing the duct that you suggested will fix it. I was going to replace that and the camshaft sensor while I'm in there, but now you have me skeptical!

 

Mine is not that bad. While driving it, you can feel it hesitating, but it never completly loses power. If you havent done the throttle body to supercharger duct yet, i would do that FIRST if i were you. On all the TSBs on alldata concerning that code that is the ONLY fix they say to do. The only reason i havent done it yet, is because it was done last month....Im starting to wonder if they didnt mess something up though.....

 

I have now changed the plugs, wires, coils, fuel filter, and air filter. I have replaced the Green gasket around the supercharger that goes between it and the throttle body tube, and also the throttle body tube itself. Also the line that runs from the throttle body tube to the MAP sensor...

I did the AGS mod which helped alot with my yoyo...

Another thing im noticing, 98% of my driving is highway, when i got the car i was only getting 25-ish MPG, over the last month its steadily dropping to the point where im driving like an old lady just to get 22 MPG....Any more ideas? I know the BPV could cause the low MPG, but what about the CEL and EML light? It would be a after compressor leak, but i would think if it was doing this to me, there would be a ton of you with CEL and EML lights on cause of leaky BPVs....Im stumped..

 

Keith, I have the same problem with my R52
I have replaced , airbox, intercooler, Bypass Valve, map sensors vacuum line etc🤦🏽‍♂️ still can’t figure it out

 

This code can be fun to diagnose as almost any component with air flow will and can cause this due to the ECU measuring air before and after the supercharger. For me this usually occurs after front end work, around the charge pipe heading from throttle body to supercharger. If the charge pipe does not seal perfectly it will cause this, if the vacuum lines coming off the charge pipe are loose and not sealing, if there is a crack in the charge pipe, cracked or intercooler boots not sealing correctly... you'll get this.

The better question i can ask, when did this occur? did you do any recent work before the issue arrived, if so what did you do as it would be easier to trace back.
You can read more of my posts regarding this here>
https://www.northamericanmotoring.co...ml#post4690001