Dkodasmit

I bought this car a few months ago and it had the check engine light on/trac off but ran great! Then I started to notice my exhaust smelled funny.
Gradually getting a loss of power (couldn't get power up hills/idle problems) I replaced the battery and terminals. That didn't fix my problem but I after that I replaced the spark plugs and ignition coils. Ran so much better for about 5 miles but started to smell what I think is lean exhaust. then the check engine/trac off light came back on and immediately felt a loss of power. Anything other information you need I'll be glad to clarify.
Please help me get this problem fixed!!

ES300NZ

pull the error code(s) from the ecu, before you do anything else.

I'd bet it's an o2 sensor, or Air / fuel *(A/F) sensor. could be a bad maf.

Dkodasmit

I did replace the upstream a/f sensor on the front of the engine. But I know of one on the back by the firewall. I haven't replaced that one yet.

ES300NZ

dont throw new parts at it. pull the error codes get it right first time.

Dkodasmit

The error codes I got were misfires on cylinders 1,3,5.
P0301,P0303,P0305.

Bank1 fuel trim too lean. P0171
Bank2 knock sensor signal problem P0330

ES300NZ

others will chip in shortly, but here are some inital thoughts,

- could the knock sensor harness (common fault) or a failed sensor (also common fault with location of the acoustic sensors)
- could be bad plugs in the back, they are hard to get too, sometimes home handymen give them a miss.
- could be a bad vvti solenoid, which has burned out the back banks o2 and a/f sensors, some 1999's have vvti some don't, mine doesn't. USA ones do.
- could be several faults at once, including damaged rear leads (spark wires).