So after replacing a new supercharger, new charge coolers, valve cover gaskets, radom new gaskets and seals, car runs fine. Let it run and idle for 20 min to bleed the coolant but while running I hear a little hiss coming from somewhere but cant really find it. Runs good though, no issues. I tured it off and turned it back on and then the CEL came on. I got p1111 and p0444 codes which looks like the hiss could be an emmisions thing which is why the car runs fine. I checked over all connections and couldnt find anything loose or disconnected. Any ideas on what those codes could be? I know that p0444 is "EVAP Purge Control Circuit No Signal" or circuit low but what is it?

 

it is a little black hose that fits to a sensor on the front bulkhead going from the throttle body/elbow to the sensor. You didn't connect it back up.
I can hear it 4,000 miles away.

Hope this helps

 

Nice one, sure that's not the rain ?

P1111 isn't a fault code - just means diagnostic cycle is complete.

 

would you be able to post a picture I can't seem to find it

 

1st pic I.D's the pipe and rough location of sensor. (pipe mid right, 'denso unit' with nipple underneath against bulkhead far right)

2nd pic I.D's the pipes and connections, the question mark is for the evap valve, the one I think might be off and vacuuming...I had the exact issue some time ago, car ran great just a hissing under the bonnet at the rear of the engine. Took a while to find the hose connection, also after a supercharger swap, that's why I think it's this - it might not be as there's a fair bit to these engines, but I hope it solves your issue

 

ok, thank you, yea I guess I forgot to connect that, either way I still have some small hiss which is barely noticeable but doesn't affect the way it runs/drives... However, I have a new weird code which freaked me out, so I plugged it back up and started it up and got a (1) new code:

1st code: P1638

I go to delete the code and as soon as I delete, I get" ENGINE FAILSAFE, LOW BRAKE FLUID, TRANS FAILSAFE, RESTRICTED PERFORMANCE, ABS MALFUNCTION" I turn the car off and same thing. As soon as I delete that P1638 code, all those errors pop up. Then I just turned the car off and went back to it about 2 hrs later and then I turned the code off and now its fine. It didnt come back, car always drove good.... however, something scary did happen when I drove it with the P1638 code. (NOT AFTER I CLEARED IT FOR GOOD). As I got on it a few times up to 80mph in SPORT mode, i let off and let it coast but as soon as I gave it gas at around 60mph, it just revved in drive, as if it wouldnt engage into a gear, I gave it gas a few times and NOTHING, just revved the engine as if it was in NEUTRAL, not untill I got to about 20mph that it was fine. When I pulled the codes right after, I got the P1638 P0730 (incorrect gear ratio) once I cleared it all and drove 1hr later, it was all fine. NO CEL, NO SHIFTING issues, NOTHING. I dont think I have anything wrong with the trans or rear end, I think the P1638 code had somthing to do with telling the car when and when not to shift since all those errors appeared on my display. Any thoughts? Right now, its fine.

 

Are you driving with the code reader connected and trying to get codes as you drive? I've seen a few vehicles that don't like that. The factory scan tools almost never seem to affect the system that they're designed for. The aftermarket scan tools and code readers will sometimes interrupt the conversation between modules in the network.

Try clearing the codes with the key on and engine off. Once clear, turn the key off and unplug your scan tool before you start it up and go for a road test. I hope it's that simple for you.

 

The other possibility is a bad battery.
A whole host of codes coming up like this is often the first indication it is on its way out.

 

I actually did do it while it was running

 

P1638 is a can-bus error, this can be a number of connection issues, but engine speed and coolant signals are missing at the IPK for this to flag. Don't run the OBD scanner while running - to confirm jchavez thought...

The car's had a little electrictronic hiccup - drive it and see what occurs, if anything. When was the trans serviced?

 

The trans was most likely never serviced but I dont think the trans has issues, it was all those codes that popped up, I believe.... TRANS FAILSAFE, ENGINE FAILSAFE.... etc, Now its all clear and fine. Why does it feel like it de-fuels between shifts. Say I get on it hard and when it shifts, it will literally pull me back and shift, it shifts fine. Kind of feels like a Chevy the way it shfits.

 

jchavez nailed that one.

The software is "supposed" to refuse to clear codes while the engine is running .. but many do not. It would actually be pretty easy to program:

if(rpm>0) abort-code-clear

 

Have you had the battery off or performed a hard reset? this would reset the trans module back to factory - and it learns your driving style. I was told by Brutal a factory tech on here not to enable Sport mode for at least 2-300 miles as the gearbox learns adaptations. Depending on which Chevy you refer to, it might have the same Mercedes box, the 722.6.
There is an adaptation procedure on here you can refer to

 

That's a very sad situation for those of us who habitually drive in sport *and* disconnect the battery frequently.

BTW, there are no Chevies that use the Merc transmission. Might have something to do with Chrysler using it as the NAG-1. The OP probably meant that it shifted like a slush box. Of course, that might be some of the recent sedans. The performance models have never been shy about hard shifts.

 

Nice to know so I did everything I shouldn't of had. Plugged OBD scanner while car was running and use Sport mode right after I disconnected the battery. Well its all fine now but should I disconnect the battery then so the trans will learn the driving habits and since I used the sport mode?