[123pugsy]

I had my Y pipe bust off on highway and ever since the car is a gutless wonder after it's warmed up. Closed loop?


On cruise control, it slows down going up hill. It doesn't automatically downshift and give throttle.
Anyone have something like this?
Car has never had an engine light on since new (05)

 

[Maleficio]

Transmission harness or connector may be damaged.

 

[123pugsy]

Transmission harness or connector may be damaged.

Thanks.

Transmission is fine. ECM not commanding throttle or fuel.



Dealer told me they found a code for knock sensors but they lied. They said that because they seen rodent twigs and stuff under the intake. $1430.00 to replace them so I told them to pound sand.



I ran the ECM reset procedure Sunday and I have at least 70-80% improvement. I'm hoping it's relearning and will continue to improve.

 

[Maleficio]

I'm gonna have to read up on this ECM relearn thing if it's any different from just disconnecting the battery for a half hour.

 

[Balazs]

I have similar problems with my FX45 (2005).
After coldstart the first acceleration is always normal, but after that it loses power significantly (even though the engine is still cold) until the next restart. When I stop the engine and restart it, the first acceleration is normal again, but after that it loses it's power.
I had a new MAF sensor at home as a spare part, so I replaced it. It didn't solve the problem, so I visited a mechanic who tried to read out the fault codes, but there are no fault codes at all and no engine light.
Then we made a test: we measured the engine parameters right after a coldstart (during the 1st acceleration) and we repeated the test after the engine has already lost it's power (2nd acceleration) and we compared the results. The only difference was that the airflow was significantly weaker during test 2. The throttle body is pretty new, so it cannot be dirty. The mechanic has no idea what's this. This car is pretty rare in my country (Hungary), there is no mechanic who is familiar with it.
Did you repair yours?

 

[123pugsy]

I have similar problems with my FX45 (2005).
After coldstart the first acceleration is always normal, but after that it loses power significantly (even though the engine is still cold) until the next restart. When I stop the engine and restart it, the first acceleration is normal again, but after that it loses it's power.
I had a new MAF sensor at home as a spare part, so I replaced it. It didn't solve the problem, so I visited a mechanic who tried to read out the fault codes, but there are no fault codes at all and no engine light.
Then we made a test: we measured the engine parameters right after a coldstart (during the 1st acceleration) and we repeated the test after the engine has already lost it's power (2nd acceleration) and we compared the results. The only difference was that the airflow was significantly weaker during test 2. The throttle body is pretty new, so it cannot be dirty. The mechanic has no idea what's this. This car is pretty rare in my country (Hungary), there is no mechanic who is familiar with it.
Did you repair yours?

Sorry that you have the same issue.

I fixed mine..............

 

[123pugsy]

The dealer couldn't fix it so I traded it in for 1500 bucks on the new (2017) Macan Turbo. This has zero acceleration issues, ha....

 

[Maleficio]

I have similar problems with my FX45 (2005).
After coldstart the first acceleration is always normal, but after that it loses power significantly (even though the engine is still cold) until the next restart. When I stop the engine and restart it, the first acceleration is normal again, but after that it loses it's power.
I had a new MAF sensor at home as a spare part, so I replaced it. It didn't solve the problem, so I visited a mechanic who tried to read out the fault codes, but there are no fault codes at all and no engine light.
Then we made a test: we measured the engine parameters right after a coldstart (during the 1st acceleration) and we repeated the test after the engine has already lost it's power (2nd acceleration) and we compared the results. The only difference was that the airflow was significantly weaker during test 2. The throttle body is pretty new, so it cannot be dirty. The mechanic has no idea what's this. This car is pretty rare in my country (Hungary), there is no mechanic who is familiar with it.
Did you repair yours?

Sounds like the ECU is retarding the timing.

 

[CBRworm]

I know this is old, but for anyone else that experiences something like this. If there is power to the brake light signal, the ECU will retard power - I saw this with a bad trailer light controller. Also, the second guy could have a bad cat.