Not going to high lift.

 

Early on in the troubleshooting process I did swap the solenoids and the brackets were fine. I was not paying attention to the AFRs when I did this; I just wanted to see if the p1145 would stop. If I swap them again should the lean behavior switch banks as well?
I've been checking the oil filter by cutting it apart and searching for any sign of metal that would point to lifters disintegrating but nothing shows up. I've also used a mechanic's stethoscope to listen to them when the engine is running and they all sound fine.
I will try swapping the solenoids and see if the banks switch behavior at all.
Does anyone know which one of the Durametric valve activation tests could possibly help diagnose this and what I should specifically listen for when I perform it?

 

Did you test the solenoids when you had them out?

 

No but I will this time. Do I just send them 12V and make sure they remain activated as long as the voltage is applied? Is the polarity clearly marked so I don't cause any damage by reversing the power leads?

 

12 volt. I do not remember which is + or -, with the connector unplugged test the contacts with key on. They are on or off. high lift or low lift. When energized you should not be able to push the plunger back in act all.

 

I picked up a new pair of actuator solenoids and installed them. I also did some repairs to the hoses going to and from the N75 to fix a boost spike. At every load and RPM level the car now runs like a dream and logs fine. I just went to my second track day and had a great time. This car continues to impress me and keeps me smiling (when I'm not pulling my hair out troubleshooting strange CELs).
Did I get another P1145? Yes, but I don't care anymore. Every 3 days or so, like clockwork...P1145. My PLX gauges let me clear CELs with the push of a button. I'm done chasing this CEL. As long as the car runs as great as it is running and I don't see any strange particles in the oil filter when I inspect it at every change that's good enough for me.

 

OK, I said I didn't care in that last post but it started getting to me because I did start to see some really fine alloy pieces in the oil filter element. I finally bit the bullet and took the car to a shop to see if it was lifter related. They did some tests, said there was a small issue with my intake lifters and then I had them replaced.
It was a nightmare...see here and after I finally got it back...if you read the link you know what happened already. I got the same damned CEL code on the drive home from the shop! Yes, another p1145. Cleared it...another hour of driving and it comes back.
This time it is different though. I am watching my AFR gauges vigilantly and the value between banks doesn't stray anymore. I am at a loss for why this CEL keeps recurring. It runs beautifully and that's all that matters.
I only posted this because I wanted to save someone else from wasting 8K on repairs they don't need and if anyone has read this far, they probably have the same code.
Now, in the words of the immortal Jeff Lebowski, "F*%k it". I'm done.

 

i ear your pain man i had the p1145 to just dont give up your maybe closer to resolv this by yourself!i reflashed my ecu,disconnected reconnect my ecu ,exhaust gasket was leaking ,new 02 sensors,boost leak to
i always check my phone with elm27 and torque app watching carefully my STFT bank one and 2 ! 10+ cycle later now , dont have anymore code ...

 

I'm interested in knowing how the shop "tested" your lifters. its possible i have a weak lifter but haven't found any way to confirm this

 

They used some of the cam activation tests in Durametric. They claimed the engine did not respond the way it should during the test and because of the p1145 I think they jumped to the assumption of bad intake lifters. After looking at all the lifters I was surprised to see they were in perfect condition. The intake lifters on our cars are a pretty cool piece of engineering actually.
All the internals I saw looked beautiful and none of the chain guides had any wear either.
I can see how these engines have a very long life potential if taken care of.

 

So you reflashed to stock, or to another tune from your tuner?
And what do you think was your ultimate resolution to your p1145, the exhaust gasket? O2 sensors? Reconnecting ECU?
I have gauges that let me watch STFT on both banks along with AFRs and since the repairs the numbers all look good.
Of course I won't give up I'm just going to enjoy driving it for a while before getting too worried about a solution.
At least I have the piece of mind that none of my lifters are falling apart and a catastrophe is not imminent.

 

thanx. my motor has a slight miss in it at 4500 to 5500 rpm. my tuner feels its lifter related and i hate to order all new arts install them to find out i still have it. ill have the shop look at the tests and see what they think

 

I'm dealing with both p1145/p1155 CEL's, I think it might be exhaust gasket issues...I believe they are emission monitor related issues as when I had Tony/EPL turn back on all emission monitors the codes came back.
Will do a boost leak check again to see if anything has opened up(should be good...fresh)...went from GIAC to EPL, same issue. New O2's, MAF, MAP, etc. last year(trying to fix same codes) and no improvement...
Turbo-back exhaust has been on/off a couple times now and I haven't replaced the o-ring gaskets yet(ya I know!)....also wonder if my secondary O2 extenders might be throwing off the emission monitor scan somehow and tripping the CEL...
MY P1145/1155 only comes on during a very light throttle ~40mph/60kph cruise...runs perfect at all times and Durametric logs show nothing odd, and have no additional info into the cause of CEL
For now I live with the CEL coming on and enjoy the car thoroughly otherwise
-Rob

 

I really wish I would have done that same thing because I could have spent that $8500 on an LSD and suspension upgrades. Now they will have to wait.
My P1145 also comes on only under light load when just cruising. I also have great looking log data and a perfect running car. The causes of a p1145/1155 are not easy to find; that's for sure.
Next mod - dime sized cut out of electric tape to cover the CEL warning light.

 

What time do you have. I had p1145 cell under light load with my giac tune. I switched to proto, and no more p1145 cel.

I have heard that giac have an update that fixes the issues (sambott let me in on this).

Interestingly, the cel always had me worried about lifters aswell. Recently pulled my engine and did the coolant fittings. While I was in there thought I would change the lifters aswell. My old ones were perfect.