reduced power/restricted performance
 

I have a 2003 "S" type it has 59000 mi.was running fine one day the next day running rough,the little engine warning light stays on, you accelerate. If you push it too hard the other amber light comes on and the car will start cutting out. the book says limp home mode.The dash screen says "restricted performance" I took it to the dealer in Palm Springs CA. They did the diagnostic on it.Thier concluclusion was a broken intake air box "bolderdash" there is nothing wrong with the box. Also the MAF air sensor was bad.I bought a new sensor and installed it even though I had my doubts. The car still perform badly, just as before. Is there some sort of reset?? or do I have other problems, like looking in the wrong place. Guys I sure need help....Thanks RonM






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RE: reduced power/restricted performance
 

How about the oxygen sensor?

RE: reduced power/restricted performance
 

badmojo ...I replaced the sensor -- air temp Part no.02C2S2670 is this the same as what you are calling "oxygen sensor" is there a reset to reset the computer?? Thanks RonM.






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RE: reduced power/restricted performance
 

what codes did they pull out of the processor?

RE: reduced power/restricted performance
 

Jag Master the only numbers that resemble a code on the diagnostic sheet are as follows---773 cpj and 59643 other than that I don't have anything Thanks RonM


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RE: reduced power/restricted performance
 

those are no good. the codes would be P----

such as P0303 or P0171 or P0174 etc... if you can pull these, lemme know!

RE: reduced power/restricted performance
 

Jagmaster--Got hold of the service writer. He was able to give me the numbers-- you hit the nail on the head the codes were-- po171 and po174 haveing to do with a lean mixture.I have already replaced the air temp sensor at the air filter box.Car still acts the same.Thanks RonM


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RE: reduced power/restricted performance
 

check for vacuum leaks and also check your fuel pressure. a common problem that we see, i am not saying that this is your problem, is that the mass air flow sensor shorts out. it reads 2 things. Barometric pressure and airflow to the engine. if you can check all these things i bet you will find your problem. if there is no vacuum leaks andfuel pressure is good (i have seen a few bad fuel pumps as well) then i would suspect a faulty mass air meter.

RE: reduced power/restricted performance
 

one more thing, the 00-02 V6 s-type had a bad problem with the pcv elbows rotting away under the intake and causing Lean codes.

RE: reduced power/restricted performance
 

also, what was the part number of the sensor that you put on? and if you can give me the last 6 of your VIN, i'll see if i can pull up some stuff for ya!

RE: reduced power/restricted performance
 

Jag Master The last five of the Vin.# M47398. The part recommended by the dealer is02C252670 I installed it and it didn't make a bit of diff. I bought an Actron Code reader supposed to be the top of the line. I find it interesting that the codes the dealer gave me were po171 and po172.The codes off the new reader are(1) PO300 random multiple cyl.misfire.(2)PO304 cyl 4 misfire.(3) PO305 cyl 5 misfire (4)P1313 manufacture control ignitions systems or misfire.(5) P1316 manufacture control ignition system or misfire. P1000 pd manufacture control fuel & air metering,aux emissions controls. This sounds a lot more like my problem than theother. Thanks again RonM

Re restricted performance
 

I too have the same problem as I did with my 2001 VDP. The VDP was a simple matter of coils on bank 1 and bank 2.

When I got the STR someone had take the K & N out and stuck a cheap genaric filter. I replace the filter with a K & N also the breather hose was broken so I replace it. The car runs fine but I was able to pull the p0171 and p0174 codes of my odb meter. Seems like this type of problem is almost trial and error until you find the culprit?

Umm... be very careful with the K & N filter.. If you don't get the oiling just right, you can cause a film to build up in the intake tract that will affect the sensors.... Some here use them just fine... From the codes you pulled, my guess is the previous person didn't oil the K & N filter properly, or you have an air leak somewhere (a common issue is the air filter box is not seated properly).

Please do some searching on this forum for your error codes. You have a very common problem and there are excellant write ups on what to do. No need to rehash everything every time.

Have you checked the FAQ's?? Very good stuff.
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I also got the same malfunction..
 

I have STR 4/2003, 90 tkm on the clock. Last Saturday I changed engine oil and oil filter. I also changed fuel filter. Both filters were Crossland i.e. not original, Today I got restricted performance and amber engine light illuminated.

I just wonder if the aftermarket fuel filter might cause this malfunction ?

Best regards

Jussi

Doubtful about the fuel filter. Are you sure you put it in with the flow arrow pointing in the right direction?

Get the codes read and post back.

While your at it update your signature with vehicle details, real easy to do.