Cursed by P0445, P0444 & P0202-HELP

[Iwantanotherpcar]

Background: Purchased 01 996tt in May with 32K, GIAC tune, Evo headers & DV’s, Remus exhaust, stock air box with K&N filter. Carfax clean & PPI good. Existing tune had a hesitation, stumble or hiccup at 3,000 RPM only under maintenance throttle. Car pulled 442.9 WHP with boost at 19.29 and fat A/F ratios (2 wd #). Tuner offered an upgraded tune and the stumble @ 3,000 RPM would be fixed. The other issue that I think is related to the curse is car would not fill up with new eco friendly nozzles but would be fine with older model nozzles.

Current situation: After getting the car back from several tunes which included new maps, new Hitachi MAF, air box and filter, the car started throwing the above codes and the stumble/hesitation migrated from only occurring at 3,000 RPM to 2,200 to 3,800 RPM, again only under steady/maintenance throttle. Testing (smoke & pressure) by two different shops of the EVAP system revealed no faulty parts.

Since the codes would still appear and the stumbles got worse the EVAP canister was replaced, the MAF sensor went back to stock and a new EVOMSit tune for a Bosch map was loaded. In the diagnostic process it was noticed that all the 6 coil packs were cracked and the plugs were fouled. The plugs had been replaced as part of the GIAC tune @ 23K. Seems odd that all 6 coil packs and plugs would be bad but it is what it is.

The plugs and coil packs were replaced before the new tune file was loaded. The new tune with the old MAF and air box has thrown the codes as well as having misfires/harder hesitations now from a low of 2,200 RPM’s to severe hesitations between 4,000 to 6,000 RPM. These hesitations now appear with maintenance throttle, steady smooth throttle application and full tilt hammering of the throttle.

The information pulled from a scan tool show codes of P0445, P0444 and a secondary code of P0202. These codes appeared each time the CEL came on. Also, loop was open, loads were light, RPM’s were usually between 3,000 and 4,000 RPM’s (one occurred at 720 RPM) and fuel levels where low although one happened about 1 mile after filling up. Boost levels are also very erratic. Sometimes full boast of 1.0 to 1.2 bars and then it’s like in limp mode with .4 to .6 bars on the stock gauge.

Please suggest what needs to be checked to get this car running properly.

My guess is that it is a small air/fuel leak somewhere that affects the EVAP system coupled with a boost leak that is somehow affecting the EVAP system and causing problems with all the tuning files. At times the car runs perfectly fine and then all hell brakes loose with the stumbles. When the stumbles occur, the ECU & tunes are trying to compensate by adjusting fuel trim and timing adjustments to try to protect it causing increased hesitations.

The other thing is the codes seem to be thrown with low fuel, at or less than ¼ tank. However, the random hesitations occur regardless of the fuel level.

It’s driving me crazy and fresh eyes are needed on this to help find areas that may need to be inspected.

[wross996TT]

P0445 98 EVAP canister purge valve - short circuit to B+

Possible fault cause

♦ Wiring harness

♦ DME control module faulty

P0446 EVAP canister shutoff valve (function) - below limit

Possible fault cause

♦ Purge air line blocked

♦ EVAP canister purge valve sticks in the opened position (this

causes continuous vacuum to go from the intake manifold to the

tank system)

♦ EVAP canister shutoff valve is blocked/sticks in the opened position

♦ Flow resistance of EVAP canister too high (filter deformed/

blocked)

♦ Pressure sensor connected incorrectly (polarity reversal)

P0202 Fuel Injector, Cylinder 2 – Open Circuit

Possible fault cause

♦ Fuel injector (coil) open circuit

♦ Open circuit in wiring

♦ DME control module

so I would check the install (wires and hoses) of the purge valve. The next guess would be a faulty DME.

[Iwantanotherpcar]

P0445 98 EVAP canister purge valve - short circuit to B+

Possible fault cause

♦ Wiring harness

♦ DME control module faulty

P0446 EVAP canister shutoff valve (function) - below limit

Possible fault cause

♦ Purge air line blocked

♦ EVAP canister purge valve sticks in the opened position (this

causes continuous vacuum to go from the intake manifold to the

tank system)

♦ EVAP canister shutoff valve is blocked/sticks in the opened position

♦ Flow resistance of EVAP canister too high (filter deformed/

blocked)

♦ Pressure sensor connected incorrectly (polarity reversal)

P0202 Fuel Injector, Cylinder 2 – Open Circuit

Possible fault cause

♦ Fuel injector (coil) open circuit

♦ Open circuit in wiring

♦ DME control module

so I would check the install (wires and hoses) of the purge valve. The next guess would be a faulty DME.

Thanks for the prompt reply. The EVAP canister was replaced but I'm not sure if the other areas were checked. I'll see if I can forward your reply to the shop. I know the wiring harness was checked because I remember this being said during our numerous converstations on the situation.

Just looking over everything in your reply, I'm thinking it's the DME.

Thanks again.

[Iwantanotherpcar]

OK, just talked to the shop and BAD NEWS.

Still has a couple of things to check but now a P0444 code appeared and will not clear.

Looks like the ECU is T*ts up!!!!!!

What are my options. Did a quick search on the net and found some places that rebuild (?) ECU. Also found some pricing on new-----YIKES.

Does anyone have any recommendations on a place that could fix my existing ECU, if that's possible!

Insite and advice would be greatly appreciated.

Cheers!

[rockjock]

Fuel Inj Latency should be checked on the maps-was there a temp change since the tune? (more then 10 deg.)

I dont see this as a hardware issue-but prob more of a tuning issue-road test tune or dyno tune?

You stated stumble is at steady thrtl position-do you have logs that you can upload? (I'd like to see RPM, IAT, Engine Loan-calculated or not), Thrtl position sensore, vehicle speed).

Sounds like you're hitting the stumble when the turbo spools to max boost and there is prob an AFR issue (too rich?).

[Iwantanotherpcar]

Rockjock, don't have anything but a scan tool (Scangauge) and it stated on Freeze frame from codes that the Loop was open, load ranged from a low of 1 to high of 7, RPM's all in the 3,000 to 4,000 range, don't have throttle position but my nose told me on start up it was running rich. Don't know about when the stumble occured.

I'll have to ask Alex if he can post. Right now he has a different ECU in the car and testing it. He ran through all the hard parts and said their fine and no air or booast leaks.

Thanks so much for your help.

Cheers!