ok so i got home, decided to take my beauty covers off for the upcoming weekend, since im replacing my control arms and a few other mics. things under the hood. i decide to do the darintake mode while im down there. so i remove the whole intake, drill some holes in the bottom half of the airbox (filter side), and put everything back together, and reconnect the maf sensor. so i start the car, and this thing (in the pics) is making a fast clicking noise from the plug. so i disconnect it, check for a CEL, and nothing. plug it back in, noise gone for about a minute or so, then came back. then for the heck of it, since i have that bad fuel milage issue, i unplug my maf sensor to see if a cel comes up, and nothing. so i plug that back in. a couple minutes later, CEL comes up. so i decide to take the car around the block and see how it feels. first time around it felt like a new car, throttle response was like i never felt before. then i stop at my house, and i figure its too good to be true (which it really was), so i decide to take it around again. so i go two blocks fine, and stop at the light on the 2nd block. while im waiting i decided to unplug my maf and see how it ran without it. so i close the hood, and put the car into drive, and when i do, it clunks into gear, HARD. so i go to creep up a little and the car has no power, so i already said to my self ****, its in limp mode. so i pull it over, open the hood, plug the maf back in, and its still in limp mode. car clunks and bucks into reverse and drive, never did that before in the 8 months ive owned it. is that normal for limp mode? what's wrong and what do i do? any help would be much appreciated. if codes are absolutely needed, ill wait until tomorrow night. i dont have a driveway/garage and we have alternate side parking, already parked it right for tomorrow. please help as much as you can with the info provided. thanks a bunch guys.

 

by the way when i put the car in neutral, the engine revs fine. the first 1.5 times around the block the car was shifting very smoothly, and in tip, the 1st to 2nd change was about the smoothest i ever felt it do. weird, like the calm before the storm i guess.. thought that little bit of info would also be useful.

 

Hey Gabe,

That's your purge valve for fuel vapors to be sucked into the engine from the charcoal canister. It should click on and off, not sure what makes the engine call for it but it is probably working OK since it is clicking (they go silent when they die).

I don't have an auto and have never experienced limp mode from an auto so not sure that I can help there. The manual version doesn't seem to have an engine limp mode that I am aware of and at one time or another I have had most things go wrong with these engines.

 

In your pic the harness goes to the purge valve and the MAF, but I forget where it goes after that on the 2.8 where it disappears between the intake duct and the airbox. Is everything reconnected under there as it should be?

 

yes it is, everything is connected right. could a bad maf or purge set it into limp mode?

 

Without the MAF the ECU will use some defaults and will run pretty rough when under load. Free revving will seem normal and idle will be irregular, probably higher. Double check the MAF connector and pins on the MAF to make sure nothing is bent. Once the ECU gets what it is looking for, everything will revert back to normal so don't worry about resetting or anything like that. Purge valves click just how you describe, so don't worry. If you wanted to eliminate it form troubleshooting, disconnect it and it won't affect the running (you will get a code though). If your car was running well and you didn't jolt the MAF in any way, it should be fine.

 

it wasnt running rough nor idling irregular. just running as it would if in 3rd gear all the time, which is what limp mode is if im correct.

 

bump. please help people! please!!

 

Ive been MIA for a while, LOL. As a thought, I know these cars are stupid sensitive, your MAF seems to be rotated different from mine. You could try to put it on the way mine is, dont know if it makes a difference or not...

Ive never had limp mode, and yeah that lil thing is suposed to click.

 

Judging by the crappy mpg you had for a while now that you talked about, it is a big possibility that the MAF sensor just went RIP after a long masked agony. Unplugging it while the engine was running and plugging it back probably jolted it, as loach warned about.

Actually what you described may pass a a first testing procedure for the MAF sensor. When you unplugged the sensor, the ECM replaced the faulty signal with a default value.
Another test is to warm up the car to normal operating temperature and put the transmission in neutral. Rev the engine up to redline in neutral. If the MAF is good, it should go all the way up to the rev limiter at 5100 rpm, if the MAF is bad, it will definitely not rev that high.

Nevertheless, at the same time, you might have other problems triggering the limp mode, while the MAF sensor is still good.
You'll have to help yourself with the codes, tomorrow, since you have the VAG-Com.
I was reading that the ECM falls back to a "safety map" when a sensor fails or sends a signal that is "out of sorts". Maybe the ECM just needs remapping after you unplugged the MAF sensor.

Probably disconnecting the battery overnight won't do any good. Or maybe it will do...

A sincere Good Luck!