Avensis 1.8 Petrol Loss Of Power

[worthy1]

I had the cat changed 3 years ago (not an OEM) and the rear box changed 18 months ago soon after the MIL light came on on checking the falut code it was P0420 cat effiency below thresh hold resetting the fault recurs after 30 miles the problem I have is there is a distinct lack of acceleration and top speed.

The engine is smooth as silk no misfire runs extremely well.

I have changed the spark plugs, air filter, fuel filter, tried catclean no improvement the car is an X reg with 117,000 on the clock so is not worth much.

I have had an OBD2 scanner on the vehicle and monitored the upstream Lambda sensor it seems to be switching OK as is the downstream one.

Any help appreciated,

Karl

[FROSTYBALLS]

Have a look at - http://www.toyotaownersclub.com/forums/topic/108268-x-reg-18-petrol-loss-of-powerfuel-effeciency-vibration/?hl=%2Bavensis+%2B1.8+%2Bpetrol+%2Bloss+%2Bpower