Ok I took my wife out to lunch. Everything seems ok as we're driving into town. We leave the car for an hour. I start the car up and, as I put it in Drive, immediately notice like a strange vibration.

As I start accelerating, it almost felt like one of the wheels was loose -- like a slight jerky motion of the car. Then I hear a putt-putt that wasn't there before -- it feels as if 15% of my horsepower is suddenly missing. The car is not really any LOUDER than usual, but the noise is different. More putt-putt. Then, as I'm driving home (feels like I'm on reduced power...) the SERVICE ENGINE SOON light flashes for a bit -- then goes away. Then I punch the gas a bit, and the SERVICE ENGINE light again. Then it goes back out.

I looked at the intake, seems ok but could probably be cleaned. I got under the car and all Y-pipe manifold connections are fine. No apparent gaps. O2 sensors are snug in place. I have not checked CAT connection yet. I did notice that the muffler was actually moving -- but I think that's unrelated -- there's a bolt missing (the one that holds the b-pipe to the frame. Surely this isn't the problem, unless it's caused the cat to seperate.

PLEASE .. I need ideas...

Going back out under the car to check cat and muffler connections...

/Anthony

 

No need. Do the ecu diagnostic. Even if the CEL is off, doing the diagnostic will split the code out. It sounds like you car was in "limp" mode for some reason.

One thing you could try is checking the maf sensor connection. If disconnected or loose, it makes the car run really bad.

 

just a guess...the vibration makes it sound like it MAY be a bad fuel injector... Happened to me once and I got the same symptoms.

 

Where is the MAF sensor connection?

I assume instructions on the ECU diag are around here somewhere..

Oh and UPDATE -- all connections (cat, exhaust, etc.) are fine.

/aac

 

would not the best idea be taking it to the dealer?

 

MAF sensor connector. Okay see the pic? Look at the left lower side of the pic. See that shiny pyramid thing? Look for the rubber connector just to the right of it. CEL diagnotics should be avail in the faq.

<img src=http://216.39.145.169/jeff/9.jpg>

 

Taking it in on Tuesday for 30k service, but this was just out of nowhere, and I'm trying to figure out what it is (and if any of my mods are to blame [pop-intake]/[y-pipe])

I just tried the ECU thing -- and I got no diagnostic -- tried like 5 times -- the light just stays steady... things get weirder...

/aac

 

The latest -- I clean the filter and put it back on the pop-intake. I took the car on a bunch of errands, even took it on the turnpike and punched it a little....

It's FINE. No sign of previous problem.

Could it have been a dirty filter?????? I wouldn't think so. Is it gone forever? Or will it come back? I'll mention it to the dealer....

Has anyone else ever had anything weird like this happen and then disappear? Did it come back? Etc etc. I'm only freakin a little because it's the first time anything like that has happened with this car.

Thanks,
/aac

 

This happened to my 4th gen max once after I cleaned the K&N / stillen intake system one of the hose clamps was loose and part of the intake system Where the maf sensor is pulled away from the maf tube closest to the engine. I looked for hours trying to find the problem until I leaned on the car and saw the hose pull away. Tightened up the clamp and my problem never reappeared.

 

So the car ran fine for the last two days (see previous posts in this thread for history) -- not a hint of a problem over the last couple days. Then this afternoon I drove over to visit my mom. Then after the visit I start the car up and get the following:

1. Weird idle
2. SERVICE ENGINE light
3. TCS OFF light
4. SLIP light

I was freaked out. I drove it like 1/4 mile then turned the vehicle off. Waited 20-30 seconds. Started the vehicle again. All three lights again. Then it seemed to be driving on low power as I drove across town. I stopped to drop my brother off, and turned off the vehicle again. When I re-started it, the SERVICE ENGINE light remained but the other lights were off. It seemed to be driving OK, not as crappy as it was during the episode a couple days ago, but not at full capacity. The SERVICE ENGINE light remains on.

I'm taking it in to the dealer Tuesday morning. I just wanted to see what you people think it might be. Any input welcome. Whoever gets it right wins a prize...



/aac

 

You will get your answer that way. My bet is it is a bad sensor. Good Luck at the dealer tomarrow.

 

if its the maf, meaning say it gets disconnected or loose , the car will run either too Rich or Lean , my best guess would probably say its running lean...