Just left my lexus dealer after getting an oil change. When I go WOT with the car in auto mode (whether or not in sport mode), it is very sluggish to downshift and when it finally does downshift, will accelerate very slowly above 4,000 rpm...almost no power.

In manual mode, no issue, accelerates great. All fluids are fine and no CEL. Gonna take it back to dealer in a few minutes..but looking for some online ideas.

Dealer has no clue what would cause the issue, they did not reset the ECU or do anything other than change oil and filter.

Thanks.

 

Is the car fully warmed up.....

 

Yes..fully warm. I was sitting in stop and go traffic for 15 min before going WOT.

 

On my way to the dealer now..it seems as though the secondary flap is sporadically not opening in auto mode. Sometimes it downshifts and accelerates fine (with the flap open) other times the secondary flap stays closed till redline. In manual mode the flap always opens..

 

My car takes longer than 15 min to warm up. Id say make sure you have 3 bars on the oil temp.

 

is it not making the growl then when its slow?

 

Full bars..i have been driving for over an hour on and off.

The car was warm from the drive the dealer takes after the oil change. The oil and coolant where at normal operating temp.

 

No growl when it is slow..

 

Keep us posted on the answer, hope it's nothing serious!

 

Just took the tech for a drive, he has no clue why this would happen. They are going to research it and get back to me.

It happened once in manual mode too..but only once. It's as if the actuator for the flap is not functioning correctly, but in manual mode it works almost every time.

In the meantime, I am going to reset the ECU and hope for the best.

 

Pulled the battery. So far so good, wot runs in auto are back to normal. Fingers crossed..

 

nothing like a reboot to make things all better, ha

 

Maybe the tech put the wrong weight oil in the car? Happened to me on my DD i felt the difference instantly and went home and drained my oil and put the correct weight in.

 

That wouldn't explain why in manual mode it would be ok.

 

I have not driven hard since picking up my kids from school yesterday, but it seems to be back downloading to the growl zone fine after the reset. I have no idea what could have triggered the issue. My only guess is that the tech mght have hooked something up to reset the service light? Not even sure my car has one tho..

The issue was directly related to the secondary flap, sometimes it would open up and other times it would not. On one run (before the reset), I went wot in 2nd gear and the high rpms were very slugish and no growl. It then shifted into 3rd and the growl and power were back to normal. Very odd stuff..

I am surprised that secondary flap made such a huge difference in performance!