asf4life

i had a problem wiht p171 on my 200 es300, have 125k miles, changed the air flow meter, light goes away, but i have been having intermittent power loss, on a cold start int he morning the car drives good, has low end power, but during the day low end power is sluggish, if i drive in high rpms i feel the power kick back in at aroudn 4rpm sometimes, sometimes it doesnt happen at all, im not getting any cel for anythign, i did a full tuneup too, didnt really do much for me, and i used dealer parts, except changin pcv valve and flushing coolant, sounds wierd but could that be it?

Lexusfreak

With your tune up, besides the plugs........what else was changed?

asf4life

changed air filter, air flow meter, spark plugs, air filter, oil, transmission fluid, thas about it, used all dealer parts, i want to fix this problem because im not feeling all 210 horses anymore

sk72

Did you also change your spark plug wires.. cause that makes a lot of difference too. I had a bad wires once and frequently I felt the car was losing it's power and regaining it.. did evrything including replacing the plugs, wires, rotors and it was fine after that. The mechanic actually spotted the wire problem which caused the performance problem. But usually you can feel the power of the car reduces like it is running on 5 cyc instead of 6.. anyways try this.. and post the results...

lexusk8

Did you try changing out an oxygen sensor, esp. the one located before the catalytic converter? Your P0171 error code indicates that the fuel system in your ES is too lean, and that one or more components inside that system has malfunctioned. If an O2 sensor is affected, it will decrease your fuel mileage, so that is usually an indicator that your O2 sensor needs to be replaced.

Pheonix

OEM sparkplug wires are extremely long duration items & will not need replacing. Only replace them with OEM, or better quality (Vitek, Magnacore).


Check for vacuum leaks, then replace the main o2 sensors.

3rdelement

iTrader: (1)

my #5 wire went bad about 10k miles ago(145k)

but yeah dont just replace them "because"