Russelltw

Forum,

I have a 1999 ES300 with about 235,000 miles. I recently had two issues pop up that I tried to resolve but have had no luck.

First Issue - rotor/brake issue. When driving (between 55-65 mph) and braking, the steering wheel shakes. You can also feel the wheels vibrating. I had new tires installed and the tech said it did not appear to need alignment. I later checked to see if the rotors were warped and they appears to have some warping (original rotors). So I replaced the rotors on both front tires, but shaking still persists. Not sure if it could be wheel bearings or what next. Would like advice on it if someone has had similar issues. Not sure if the tech who replaced the tires even checked alignment. Would like to get rid of that shaking.

Second issue - P0171 CEL code. I have cleaned the mass flow sensor, then replaced mass flow sensor. Keep getting the code, so replaced air/fuel sensor (the difficult one to get to between firewall and engine), yet still have this error popping up. It triggers in combo occasionally with the P0446 code. I have reset it several times via bluetooth code reader. Sometimes it triggers P0171, other times it is P0171 and P0446. Mileage has not dropped. Was recently on a long trip (interstate mileage) and was getting 26 mph.

Recently replaced all 6 spark plugs and the back three ignition coils due to CEL codes. Not sure if it would be related, but wanted to mention it also.

Any thoughts would be greatly appreciated.
R

hzt30

First issue - even though you replaced front tires, to rule out tires/rims rotate front tires to the back and see if there is a change. Check ball joints and stabilizers for wear. Also check inner and outer tie rods.

Second issue - P0171 is a lean condition on bank one. When you get this code check the freeze frame data. Do you get this when engine is hot or cold, under heavy load or light load, etc? Check your long term fuel trim at high RPMs and at idle. If long term fuel trim is normal at high RPMs but high positive at idle then this could mean a vacuum leak. You could also have a fuel delivery problem.

Wht95scort

Vibration is due to your front rotors being out of round. If they are still in good shape you can have them cut. If not then you will need to replace them.

P0171 you most likely have an exhaust leak. Have a shop perform a smoke test to find the leak.
P0446 is an evap code most likely your canister vsv valve went bad. Have a shop also perform a smoke test on the evap system.

clintbw

In hopes of being relevant to this case, my P0446 code was caused by the connection from the Charcoal Canister to the Air Filter Box VSV breaking off. Apparently when I changed the air filter, the plastic connection broke off into the hose and could no longer be secured, so it was just dangling under the hood.