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Tim Mohr
Tim Mohr, ASE Master Tech
Category: Honda
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Prelude: 1989 Honda Prelude Si -- 425,000 miles O2 trouble

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1989 Honda Prelude Si -- 425,000 miles
O2 trouble codes. Slight surging (speed) on highway
Hello, I recently replaced the original never-changed 02 sensors. No prior problem, mechanic friend said they should be replaced.

Check engine light comes on after 2-5 minutes and codes 1 and 2 flash on the ECU. Slight surging on the highway at 65 mph but no discernible rhythm or pattern to it. Random but frequent.

Checked sensors for contamination but none that I can see. (Can send pic.) Connections seem ok. Do not know how to check output from sensors.

Wrong or bad aftermarket sensors? (There are two; both on exhaust manifold.)

Replaced EGR valve yesterday after trouble code 12 that I ignored for many months. Seems to be more power now than before.

Starts, idles fine.

What to do? What to do?

Hi, my name is XXXXX XXXXX have seen this problem with after market o2 sensors on these, particularlly with the Bosch after market, was this happenning before you did the o2 sensors?
Customer: replied 4 years ago.

No. Everything worked fine before I replaced them.



Then i would replace them with factory o2 sensors, the originals lasted for over 400k miles, we have seen this alot on the aftermarkets for this vehicle, we have used after market for the domestic cars, but on Hondas and toyotas, we ALWAYS use factory,Tim
Customer: replied 4 years ago.

Thanks. That's helpful. A big difference in price between after market part and factory part as I recall. Could have something to do with quality.




Many thanks.

absolutely, you get what you pay for, but we do use these on the domestic vehicles with good success, but the Hondas dont like them,tim
Anytime my friend, glad I could help,Tim
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