Chevrolet Cruze Forums banner
1 - 20 of 25 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter · #1 ·
U0140, P2227, P2228, P0420, P0299. Ive replaced many parts to include the turbo all the lines coming in and out, rerouted the check valve on the intake manifold, MAF sensor, baro sensor, map sensor, turbo boost sensor and probably more just cant think of any more at the time. I know the P0420 is an exhaust leak/gutted catalytic converter i created when replacing the O2 sensor after the catalytic converter. I gutted the catalytic converter because i thought maybe it was bad then changed the rear O2 sensor and ended up having to cut the exhaust and pull it off to remove the O2 sensor because it wouldnt come out. I pulled the brake booster hose out as well and blew smoke with my vapor cig in there with no visable leaks, dont know if that would replicate a smoke test to the extent it needs to but afterwords pulled the intake hose off and there was smoke in there (so i think it worked) Any questions and ill do what i can to answer them. I will appreciate all the help i can get.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #6 ·
Why it wont boost over 4 psi
It is possible the bypass valve spring has gotten weak, but I would wait for more techs to chime in, I am not a mechanic.
Im getting all the codes as posted above, with a mechanical boost gauge showing 4 psi. This might or might not be related but the DIC is showing a average of 17 mph. The average mpg shows 29 (i believe ill check again) but i can almost see my fuel gauge dropping while driving it seems to me to be getting terrible gas mileage. I can go through about 1/4 a tank and drive at the most 80 miles.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #7 ·
You have done a lot! What are the symptoms you're having? As in actual running problems?
Also forgot to mention that if i pull the vacuum hose off the waste gate actuator ( wont do it again as i know i playing with fire) it will boost properly. Im thinking at this point its going to be a computer issue, but just my opinion.
 

·
Registered
Joined
·
14 Posts
I wouldn't think the wastegate spring to be bad straight from the factory, though I've seen it before...

I've had the underboost problem before but it went away, and I still have the P0420 and it makes my car run horrible at higher RPMs...

In your case, I would definitely lean towards the bcm or ECU since you changed the baro sensor already and there are two codes for it.

That being said, I feel you have two different issues going on, but it could all be stemming from a bad ECU. Not the gutted cat part, but the underboost and bad barometer readings.

Just my two cents.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #10 ·
I wouldn't think the wastegate spring to be bad straight from the factory, though I've seen it before...

I've had the underboost problem before but it went away, and I still have the P0420 and it makes my car run horrible at higher RPMs...

In your case, I would definitely lean towards the bcm or ECU since you changed the baro sensor already and there are two codes for it.

That being said, I feel you have two different issues going on, but it could all be stemming from a bad ECU. Not the gutted cat part, but the underboost and bad barometer readings.

Just my two cents.
I appreciate the help. Is there anyway to check that spring? Something else i didnt mention is oil in the throttle body, intake manifold etc...
 

·
Registered
Joined
·
14 Posts
I wouldn't think the wastegate spring to be bad straight from the factory, though I've seen it before...

I've had the underboost problem before but it went away, and I still have the P0420 and it makes my car run horrible at higher RPMs...

In your case, I would definitely lean towards the bcm or ECU since you changed the baro sensor already and there are two codes for it.

That being said, I feel you have two different issues going on, but it could all be stemming from a bad ECU. Not the gutted cat part, but the underboost and bad barometer readings.

Just my two cents.
I appreciate the help. Is there anyway to check that spring? Something else i didnt mention is oil in the throttle body, intake manifold etc...
With you having oil going through the system, that can really hurt the cat and cause it to clog and break down, if you don't have it hollowed it... So that might be contributing to P0420.
 

·
Registered
Joined
·
14 Posts
Oh, and for the wastegate spring, if the car is operating the same since before the turbo swap, I'm fairly confident that those components all work okay. But since you have the old one, you could in theory take that one apart and try to figure it out, then compare if it isn't too invasive?
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #13 ·
Oh, and for the wastegate spring, if the car is operating the same since before the turbo swap, I'm fairly confident that those components all work okay. But since you have the old one, you could in theory take that one apart and try to figure it out, then compare if it isn't too invasive?
I hollowed out the cat, just to eliminate it being a bad cat. I dont have the old one but it was cracked by the wastegate, typical from what ive been reading.
 

·
Registered
Joined
·
14 Posts
The pcv sticking could be a reason for oil in the intake for sure. And also cause a minor intake issue. 4 psi limit worth, I don't think so, but it would hurt to replace.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #16 ·
The pcv sticking could be a reason for oil in the intake for sure. And also cause a minor intake issue. 4 psi limit worth, I don't think so, but it would hurt to replace.
That might be my next new part. It really seems to me either one its a leak that is really consistent or 2 like i said before its a computer issue because i can take the vacuum hose off of the wastegate actuator and it boosts just fine, leaving me to believe the computer is keeping the wastegate open but not fully open (i.e. like 10% open)
 

·
Registered
Joined
·
14 Posts
I will say, I believe the wastegate is spring closed and pneumatically opened. That being said, you can check it with air or by removing it and checking it with a spring scale. Both ways require removal, but that's an easy way. The hard they are to actuate, the more boost. So if there isn't any force to actuating it, it's probably a weak or defective spring.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #19 ·
Oh, and a cheaper route, before an ECU, may be a new boost solenoid/boost controller.
The boost solenoid/controller was new with the new turbo as well as i swapped it out with others. Im unsure as to how i can test that spring inside the wastegate actuator but will see if i cant figure it out.
 
1 - 20 of 25 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top