3 codes being thrown intermittently

[slay2k]

My 2001 Jetta 1.8T threw its first CEL a few months ago. I had a local mechanic reset it w/out a VAGCOM, after showing a (P0172 System too rich bank 1) generic code. I've since bought a V-Checker V202, and a couple months later (two days ago) it threw what I suspect is the same CEL:

16712.P0328 Knock sensor 1 circuit bank 1 - G61:high
17705.P1297 Connection charger to throttle valve: pressure dropped
17545.P1137 Bank 1 mixture adaptation (add): system too rich

That's the reading off the VAG. I've reset it and have been driving with no CEL for a couple days now, and suspect I may not see one until another month or two.

Does anyone know what that combination means ?

[slay2k]

bump

[Scigano]

I looked up what the third code (at least by itself) has typically turned out to be — and the Bentley Manual itself said this:


-Check fuel pressure control and holding pressure
-Check fuel injectors
-Check Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-"

Knock Sensor 1: Value Too High + that raises a question or too: did you feel the engine knocking, notice any sudden drop in power or response?

Connection to Charger and Throttle Valve: Pressure Drop means the ECU thinks there was a boost leak (or at least suspected it since the system suddenly went rich — which it could have if the computer was adding fuel for boost that suddenly decreased, skewing the air/fuel ratio to more fuel than air).

Have you got a boost gauge?

*bump to keep this near the top*

[slay2k]

I looked up what the third code (at least by itself) has typically turned out to be — and the Bentley Manual itself said this:


-Check fuel pressure control and holding pressure
-Check fuel injectors
-Check Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-"

Knock Sensor 1: Value Too High + that raises a question or too: did you feel the engine knocking, notice any sudden drop in power or response?

Nope. This one happened during idling at stoplight, didn't hear any kind of knocking and there was no drop in power afterwards.

I suspect that, because the codes were thrown all together, and because I've now driven weeks without any kind of symptoms (or codes), that this is all caused by a single issue. Oxygen sensors maybe ?

Connection to Charger and Throttle Valve: Pressure Drop means the ECU thinks there was a boost leak (or at least suspected it since the system suddenly went rich — which it could have if the computer was adding fuel for boost that suddenly decreased, skewing the air/fuel ratio to more fuel than air).

Have you got a boost gauge?

*bump to keep this near the top*

No boost gauge, stock Jetta.

Thanks for the reply.

[Scigano]

That is a tricky possibility (that it's one thing, not necessarily your primary O2 sensor). VAGCOM certainly makes diagnosing things easier, but it's not guaranteed to be right every time (just do the best it can).

I kept getting torque limit exceeded codes, hard limp, and a failed O2 sensor code every time I booted more than 5 psi below 3,000 RPMS. Turned out to be my GIAC tune, which pissed the hell out of my car apparently (diehard Unitronic guy now).

A boost gauge could've helped, but if this happened while just at a light and the car drove (as far as you can tell) the same before and after, I doubt it's a new leak that just sprung up. How old's your car — when they get into their golden years, a car w/ this much computer control and sensors can have the occasional hiccup (that gives you the willies none the less).

If the codes were cleared on VAGCOM last time, maybe you should scan again to see if any "soft codes" are lying in wait for you.

[slay2k]

That is a tricky possibility (that it's one thing, not necessarily your primary O2 sensor). VAGCOM certainly makes diagnosing things easier, but it's not guaranteed to be right every time (just do the best it can).

I kept getting torque limit exceeded codes, hard limp, and a failed O2 sensor code every time I booted more than 5 psi below 3,000 RPMS. Turned out to be my GIAC tune, which pissed the hell out of my car apparently (diehard Unitronic guy now).

A boost gauge could've helped, but if this happened while just at a light and the car drove (as far as you can tell) the same before and after, I doubt it's a new leak that just sprung up. How old's your car — when they get into their golden years, a car w/ this much computer control and sensors can have the occasional hiccup (that gives you the willies none the less).

If the codes were cleared on VAGCOM last time, maybe you should scan again to see if any "soft codes" are lying in wait for you.

Car's a 2001, and I'm not quite sure how to scan soft codes with this V-Checker.

[Scigano]

Soft codes are just VAGCOM codes that the ECU stores, but don't throw CELs. They'd show up all the same on VAGCOM. Had any hiccups again recently, or noticed any change in idle, drivability, or power?

[slay2k]

Soft codes are just VAGCOM codes that the ECU stores, but don't throw CELs. They'd show up all the same on VAGCOM. Had any hiccups again recently, or noticed any change in idle, drivability, or power?

Nope, been driving fine just like after last reset. I expect it to throw again in a month or two... not sure how to diagnose ? :/