check engine

Check engine light has turned on.

Mechanic I trust said code indicates the catalytic converter is bad (code is P0420). He said that code is pretty straightforward as far as trouble goes. He turned light off, but it came back on about a week later.

Is there anything short of a bad converter that would turn the check engine light. Car has 170000 miles, purchased new.

1996 Camry, 4 cyl AC, PB, PS Auto trans
Reply to
stevie
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Bad batches of oxygen sensors can do this. Later years had a TSB. Sensors and converter changed free within warranty. But 96 in any case is probably out of luck (might want to check with the dealer).

It may be the converter, or it may be your oxygen sensors. If the cat passes smog test as in a case I came across I'd just change the sensors be done with it. If so replace the Denso thimble sensors with Bosch planar sensors. I'd avoid Denso sensors like a plague (but they do make excellent alternators). Bosch planars have vent holes only at the tip and IMO are best-in-class.

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You also have to make sure your car is properly tuned up. Timing belt, plugs, the works.

stevie wrote:

Reply to
johngdole

Bosch planars have vent holes only at the tip

=========================== Bosch introduced those in 1997 seemingly with different voltage characteristics.

Be sure they're compatible with the 1996 engine management system.

Not sure about the 1996, but my 1994 is unheated whereas the planar are heated.

Reply to
Daniel

You're right Daniel. Parts catalogs suggest 96 uses unheated, 2-wire sensors. But if planars are an option, I'd always use them in place of thimble sensors.

Daniel wrote:

Reply to
johngdole

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