I tried to give my evo a boost leak test this afternoon and thought as was going well. Found a few leaks got to tinker around in my engine bay. I thought all was good until I forgot to disconnect my valve cover breather and I'm sure somehow I screwed something else up too. But when I gave it a spin around my block afterwards to check it out I noticed something much worse than before... My engine sputters on start up and gives when I put on the throttle. When I get to higher speeds my exhaust gives some backfiring noise. Now when I hit boost at around 4500 rpm I get a popping noise and loose all power in the gear. I feel like I killed my car. HELP!! Im thinking I might have given myself a bigger boost leak than I had to begin with. All I took of to do the test is my cold air intake and the diverter hose to the cold air.

 

I also found my cold air intake sensor popped out of the bottom of my intake. I put in back in but I still have the same problems....

 

Check over all of your clamps and vacuum lines making sure all connections are tight.

 

Did that. Twice. I tried reseting my ECU and im going to see what that does for me.

 

Check if u conected ur maf, sounds silly but it happened to me and I was getting the same symptoms

 

Ok. Newbie here. where is the MAF connection located? Resetting the ecu got rid of the engine hesitation and sputter on start up but I still cannot hold a bit of boost it seems like. I feel like im driving a 1974 volkswagen jetta right now. And let me tell you...it sucks.

 

It would be connected between your turbo and air filter on the intake. Its about a inch long and clips into the MAF housing.

 

its not that hard where your intake pipe is that connects to the turbo theres a round black plastic piece that has a square on top of it thats your maf sensor....plug it in with the loose connector hanging right by there. As for the boost leak, sounds like your problem is due to air escaping out the ic piping, for future reference if your gonna do a boost leak test, use soap water and a spray bottle spray it on areas on the piping you think is leaking... and pressure test it to where your car boosts...cuz some leaks might only happen when you hit that high and not any lower. And for when your tryin to fix your leaks spray some hairspray on the ic piping before putting couplers back on and tightening them down. Now are you using tbolt clamps or stock worm clamps?

 

Yea this had happened to me as well, and it was the MAF sensor I forgot to plug back in after I had taken off the air filter. I noticed you said you checked everything twice. But sometimes when your worried or working fast you can easily over look or make the same mistake many times. Just chill out for a bit then go back and take ur time re checking all of your hoses and connections. Good luck dood =)

 

Sh*t! right when said plastic connection, I forgot to hook back up after taking out my cold air. I think this might do it. Lemme go give it a whirl


Yeah turns out you were exactly right on the MAF not being connected. Before the boost test I could hold a fair amount of boost, could that disconnection cause the boost and rpms to cap out at 4500 prm?

 

What's up bro barely noticed your message and ....yeah it does sound like your maf isn't connected....lol that's happened to me once I remember thinking my car was screwed up haha till I plugged it back in....haha

 

Hah. I was about to call you and tell you my car was dead. I was out in my shop working on it until like 2 am this morning. My revs could be heard for miles. Im about to go give it a spin and see if that was the culprit. Im sure it is.

 

Haha my neighbors from across the street hate when I work on my car, because of the revving...

 

I cant see why no one wouldn't WANT to listen to me rev...When I rev my car its like the sound of two walruses at the peak of mating season. Its a sight to behold for sure.

 

With the MAF sensor unplugged my car would barely run at all. Trust me. It's your issue if it wasn't connected.