So, a while back my car was running somewhat rough and I finally got a CEL with codes 1109 and 1250. I read a lot of posts and found the 1109 pointed to the MAF, and I was so sure it was gonna be the problem, I preemptively bought a can of electronics cleaner. After checking the voltage, it read 1.01 off, and 1.38 running, so no issue there (I thought). Next up was boost leak check at the turbos. It wouldn’t hold air at all . Such a loud leak, I thought my compressor was leaking! I found the passenger side IC hose from the Y-pipe blasting air, so off with the wheels, bumper, and wheel well liners.

I had recently changed my IC’s to the GT2RS ones and obviously did not reattach that hose properly. I found the same problem on the driver’s side ! They are not as easy to seat as it appears! I recommend you really pull on them to make sure they do not pop off. They also do not seat as tight as I would expect, but they did hold pressure….until I pressurized my system to 15psi! At that point the passenger side IC hose leading to the Turbo popped off . Obviously the same issue upon reinstall after GT2RS’s! After I reattached that one, the system appeared ok.

The 1250 code is a boost issue, which could also be the wastegate actuators hung up, but my AMS WG’s were fine and the lines securely fastened by zip ties as I did when previously installing them. I ran the car with smooth boost and no issues, and the CEL did not return . However, the car was still running a bit rough, so I installed a new OEM Bosch MAF. This fixed the issue. So, a note to those of you who test your MAF and get “normal” voltage readings!

Fast forward to last weekend. While out on a spirited drive to enjoy the California weather (about the only positive thing left in this state), I noticed my bar gauge blip to 1.5 (normal 1.2) after a run to red line in 3rd gear. Having been informally educated by many on this site (Markski being the lead instructor), I immediately thought boost leak. So, back to the above procedure (sans removal of bumper), and on with testing kit at turbos!

The attached photos show what I found at 10-15 psi: leaks at wastegate tubing on drivers side and a leak at the MAP (Manifold Absolute Pressure) sensor. I reinforced the tubing with additional zip ties. I removed the MAP sensor (screw secured with blue Loctite) and just did some cleaning around the area and connection points to the Y-pipe. I then slid the green rubber O-ring (shown in one of the photos) down (closest to the sensor itself). It has about 1-2 mm of play. I then simply reinstalled it, although I will likely just replace in the future as it looks like about a $20 part.

I retested the system and it held to 15 psi. Between 15 and 20 psi, the IC hose between the turbo and IC began to leak and I could not get it to seal . The gasket was replaced when I fitted the GT2RS coolers, so I guess I found the limit of the stock hoses! New Samco’s are likely in my future! I still have not fabricated a test kit for the air intake opening, or TB, but it is on my list.

In addition, I recommend supporting your test kit with a piece of wood between a point on the frame and the cap (you can actually see a part of it in one of the photos. That way, it will prevent the kit from popping off and, 1) scaring the bejesus out of you , and 2) smashing your pretty psi gauge (ask me how I know) or some other part of your car ! I hope this information is of use to some of you.

On a side note: I know Markski has been asked to post a video of what a “normal” sealed system looks like on the psi gauge. I know the system (at least from the turbos) does not hold 20 psi for minutes on end. So, here is another such request Markski!

 

MAP Sensor!

 

Great work and persistent troubleshooting. Good feedback on the MAF measuring correctly but still needing replacement. Other than samco hoses, what other options are out there for aftermarket intercoolers?

 

Where and how does your MAP sensor leak?

 

MAP sensor sits right on top of the Y-pipe just before the TB. Check out the first picture in my second post. It's leaking right out the front (right) side, opposite the side with the screw. Single screw design could be better with a screw on each side IMHO. The last picture is the after shot - no more leak.

 

I'm looking at the Forge ones. I have heard good things and they are almost half the price of the Samco's. I have also read good things about the new OEM hoses. My understanding is they made some improvements in design. Maybe someone can confirm this?

 

fully agree! they may LOOK properly connected but yank on em! i went thru a similar process of discovery. mine was not tight at the y-pipe ( though i also had the i/c hose(s) pop and had to search for the 5$ c clips! ) but since reconnecting everything i also have an extra .1 ( average) of boost, and will be watching that carefully also.

but i sure wouldn't clean my maf by spraying stuff on it tho... but if it works? more power to you

...oh... then NEW MAF! way to go bud....

 

Thanks for that im very interested in knowing how you fixed the leak on the MAP? Thx

 

Good job and imagine if you took the car to a indy shop to install the gt2RS intercoolers... how much labor would you have to spend this second time if not the third just to swap for new hoses? Im guessing well over $2500 installed and for that you can get some bad *** ICs... period... do it once do it right... I can't harp enough about this as a many see the $1400 attractive price for the gt2rs and think they are a 1,2,3 to install.. I know your issues.. I have clients with similar problems... and the 996 hoses have tendency to pop off - at least the 2 clients Ive seen both had the pass. side hose not secure... and both had a INDY P car shop do the install....
If one wrenches its not an issue you can take your time and do it all over again...
a little note: do not assume that any or all AM boost hoses will fit either... be aware....
good luck
markski

 

I think I'm gonna go test my system right now. What hoses work best with these GT2RS IC's? Mark, you put the OEM hoses back on my car after my Agency Power hoses sucked pretty bad.

 

Right we had no options and I don't use those Intercoolers.
It still was as a challenge. Popped off on me once. I do know that the aluminum ends are different between 996 and 997 hoses.

 

Sorry I was unclear - I just unbolted it, cleaned the area where it connects with Y-pipe, readjusted the O-ring and reinstalled. This made it hold pressure afterwards. However, like I said, I will likely just replace the part as it will probably leak again. Markski, have you experienced a MAP sensor leak? I have not heard you mention it much.

Yep, did the labor myself! Thanks for the input Mark! It's mostly thanks to you I was able to locate them! You got any video of what a psi gauge will look like on a system without leaks?

In speaking with a reliable source here on 6speed, who has done extensive testing with the GT2RS coolers, as far as AM hoses he said Samco is the best fit, but Forge will also work but is a tight fit (which is better than the opposite)! Based on my earlier post, I will likely be sourcing the Forge hoses.

 

I picked up the Forge hoses from USP for 400. With shipping, 424.

 

^^^ Nice, I just looked at their site. I saw the VENAIR hose kit their also, anyone use those? So options as I see are Samco, Forge, VenAir, 911Tuning, whom else???

 

Nice find! Cheapest I found was $450 so far.

I found VenAir also, but on another site. I have never heard of them. Which, in my mind means, don't buy - but that's just me.