1997 Toyota Avalon poor performance

CROWE

MEMBER
1997 TOYOTA AVALON
6 CYL
FWD
AUTOMATIC
17,000 MILES

Car starts and idles fine but is very slow to accerate and cat. Converter get red hot. Already replaced converter and fuel pressure damper. O2 data is good, long term ft and short term ft is good. Timing is good. Maf 97 gps at wot. Egr is good. New plugs wires and coils. Injectors and injector pulse is good. Fuel pressure is good. I will be more that happy to make a donation if I can get a good answer.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Hesistating, stumbling, jerking, lacks acceleration etc-below could be the caused of your problem.

Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires