As some of you may know, and others have also experienced, Rufus was getting an occasional CEL 1140 code ("improbable load sensor values"). After trying everything, including a new MAF, I think the problem was corrected when it was discovered that there was a K&N air filter in there, and I had a factory Porsche paper air filter installed in its place. I can't be certain that it is fixed because the problem is reported just every once in a while. But knock wood, no CEL 1140 so far in 700 miles or so.

Anybody else have this strange 1140 code? Check for a K&N filter.

 

I've never had the code. But my car came with the K&N filter from RUF too. I changed it back to the Porsche filter recently too. Because the K&N is black, I cannot tell if it is dirty or not. And it has not been replaced since I bout the car 10k miles ago, so it was time for a change!

Fingers crossed that you don't have the code again.

 

Hey Steve, after I purchased my Turbo from Thomas (Rennlister "md11plt") back in November 2009 I got a CEL P1140 code on my way home from Atlanta to Chicago. Mileage then was 33,000 miles.

It happened on day 2 of the trip, just north of Knoxville, raining, cruise control on, starting to head up a grade. After I got done freaking out, and talked to Thomas on the phone, I phoned ahead to the Porsche dealership in Lexington, KY (since closed down). Thomas never had this issue during his 2-3 year ownership.

The Lexington Porsche dealership cleared the CEL and stated it could be 1 of about 3 different things, including the slippage of the alternator belt.

When I got the Turbo home on day 3 I took it right to my mechanic, as I had always planned to "zero" out some pro-active scheduled maintenance. One thing he noticed was the alternator belt was slightly glazed, slightly cracked and did not have the proper shims (for proper tension). All this was replaced.

That was about 17,000 miles ago and never again have I seen the CEL or experienced any other fault codes.

I remember researching this P1140 code on Rennlist during the time, and a few owners had experience this very elusive fault code.

My Turbo has always had OEM air filters.

 

I had this code come on and it took forever to diagnose. I had Joel Reiser in Rochester do a vacuum leak test and it wound up just being a loose hose and an easy fix. Hope yours is as simple, but before you waste any more $ find someone who can do that test for you. Do a search on here for that code #

 

Slightly off-topic, but did you guys know that the engine air filter should be changed when the clutch is replaced? If it has been slipping, and smelt, it has something to do about the shared airbox (not sure the term) and can cause the filter to be dirty.

When my clutch (and a LWFW) was replaced last month, this was done. My clutch was only ever so slightly slipping when on boost.

 

since we are talking about CELs....my stupid car is throwing all kind of 02 sensor problems from inadequate voltage to heating errors. Fronts are basically new, rears never had any issues before the car sat outside in the rain one night.

Harness recall was done.

car runs fine.

Any ideas?

 

See, I've always said Porsches should not be driven in the rain! I don't call myself No HTwo O for nuttin.

 

Oliver, long shot, but what about the cylinder temp sensor 993-606-013-00 price $181.55?? Kevin has mentioned that these are now getting age on them.

 

always a possibility.

I'll check the sensor values tonight.

At least it keeps me out of trouble.

thanks for the tip.

 

I'm wondering if Ruf equips their Turbo Rs with K&N filters, and if this is a potential problem. I know that Viggo (Turbo R) had an 1140 code problem, but I don't know if he has the K&N filter. I know that Texas993 (Turbo R) had a K&N filter, but did not have the problem. I would love to gather more data.

 

Steve,
I'll check tonight and see what air filter I'm running. So far no 1140 code problems... Hope your swap fixed the issue!
Kevin

 

I've got a K&N Air filter on my turbo, and I don't even have a clue of what you guys are on about. Is this good or bad? Where should that "code" thing appear? OBD? OBC?

Thanks

 

Your "check engine" light will illuminate. And the code will show P1140 when read with the proper device and software off the OBD.

 

Oh okay thanks. Actually my check engine light comes on frequently but it is always related to the exhaust. The FVD I have installed sometimes causes it to get high CO readings.. All that lambda sensor business etc..

 

fpcruz,

There is some lively debate about the K&N and BMC aftermarket air filters as opposed to the stock Porsche paper ones. Here is the quandry, as I see it: If Ruf uses the K&N as a standard part of the Turbo R conversion (still not confirmed, but seems like it), then there must be some benefit to the K&N. However, the oil from the K&N filter can contaminate the MAF wire and lead to issues, such as the 1140 CEL code. All of this is purely speculation, but in fact replacing the K&N with the paper filter has cured my 1140 code issue.