1999 Toyota Camry HESITATION

WHUSTON

MEMBER
1999 TOYOTA CAMRY

Shakes or Wobbles problem
1999 Toyota Camry 4 cyl Front Wheel Drive Automatic

My 1999 Toyota Camry hesitates when I accelerate, and wobbles around 65mph. I have not had my fuel filter changed in a while. Just wondering if that can be the problem.

Also my check engine light has been on for a while, and the code reader gave codes po125, and p1135. I was told that the p1135 had nothing to do with my year vehicle, and to concentrate on the po125. I changed the upstream o2 sensor, as recommended by a toyota specialist, and it seemed to have fixed the problem, but about 30 miles later the check engine light came on again. I believe the new o2 sensor helped because the last 2 times I had the codes cleared, the check engine light came on after 2 miles of driving. I was told by another mechanic that the po125 can be several issues, including the fuel injector and filter. Can I have the injector cleaned, because I really don't have the cash to purchase a new one after purchasing an o2 sensor for $150 bucks, but I have to have this check engine light off to get an inspection for my registration.

My car also has a funky smell that comes out of the exhaust after initially starting it. Help!

1 Reply

MMPRINCE4000

MECHANIC
8,549 POSTS

Ok, this is weird.

My code library shows the P0125 code on a Toyota as "Insufficient Coolant Temp for closed loop fuel control"

This simply means that the coolant is not reaching operating temp and therefore the PCM is not going into "closed loop".
Closed loop means that when engine reaches proper temp, the PCM takes control of engine (timing, fuel control) using sensor feedback.

When not in closed loop, the engine is run off a pre-determined set of timing and fuel control without regard to sensor feedback (called "open loop"), until the engine is at operating temp.
In open loop engine fuel is on the rich side and timing is preset by PCM until closed loop is achieved.

This could simply be a bad thermostat.

Have your Toyota tech tell you what the P0125 code is.

If engine never goes into closed loop operation, it will cause hesitation, rough running because the fuel mixture is rich. Running in open loop all the time and at a rich mixture will also cause (eventually) convertor to overheat and fail.