1997 Toyota Corolla O2 sensor problem

1997 TOYOTA COROLLA
156,000 MILES • 4 CYL • FWD • AUTOMATIC
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MMERTEN
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Ihad just replaced the head and did a valve adjustment, I didn't find any valves that were on the tight side, but now both of my O2 sensors are actioning up, i had the codes pulled and it said O2sensors and or running to rich. any ideas? could there be a problem with intake leaking?

thanks again,

Mike Merten
Oct 29, 2008 at 9:31 AM
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MMPRINCE4000
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If the intake is leaking, you should have a vacuum leak and higher than normal idle. You could also have an injector seal leaking.

The valve adjusting shims MUST go back in the same position they were removed.

If the head was replaced because of a leak and coolant got into the cylinders, that could be the cause of the O2 sensor problem.
Coolant will ruin the O2 sensor in short order.
Nov 1, 2008 at 8:10 AM
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MMERTEN
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i had messed up the shims on install but put them back to correct position when checked for correct gaps, there still is a little bit of ticking but not as loud as before i did the adjustments. the head had a bad seal but nothing made it in to the cylinders, they were clean. could i do a compression test? to see if the new head gasket is bad? or just spent the money and hope that the O2 senosor work?

Thanks again for the quick reply.

Mike
Nov 1, 2008 at 9:00 AM
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MMPRINCE4000
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Run a compression test to make sure the head gasket is seated and not leaking.

Check valve clearence on a COLD engine. You can purchase new shims from Toyota if needed, also make sure the timing belt is on correctly, if off one notch it will make a lot of noise.
Nov 2, 2008 at 7:24 AM
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