Rev hang and oxygen sensor

[Anthony]

When I reinstalled my anaconda down pipe after passing emissions I damaged the clip on the oxygen sensor. It plugs in just fine but I don't believe it is secured as well as it once was (due to the clip breaking).

I've noticed a little more rev hang lately along with a slight loss in MPG. No check engine lights. Could this all be related?

 

[BigLee]

Are you talking about the clip that holds both halves of the connector together, or the clip that attaches the connector to the bracket?

 

[mja]

When does this rev hang happen, at all rpms?

My first thought if you're not throwing O2 sensor codes is exhaust leak

 

[Anthony]

Aha! It just threw an O2 sensor code.

I broke the clip that holds the O2 sensor to the bracket. Still think it's an exhaust leak?

 

[mja]

What code? What rpms are the revs not dropping?

The clip that holds the O2 sensor connector to the water outlet housing breaks easily, gets hot, no big deal. I zip tied mine to the housing and it works fine. If the sensor is more than a few years old, or has around 60-80k miles could be time to replace (the front one). Especially if it has a layer of char or mess on it.

I'd go back over connections on the exhaust to make sure there's no leaks, loosen and re-tighten. If there's no thumping or knocking sounds, may not be exhaust leak. I've had revs hang from a worn out clutch before too. Last thing would be vacuum leak. Hard to say whats goin on, could be 2 unrelated things.

 

[Anthony]

What code? What rpms are the revs not dropping?

The clip that holds the O2 sensor connector to the water outlet housing breaks easily, gets hot, no big deal. I zip tied mine to the housing and it works fine. If the sensor is more than a few years old, or has around 60-80k miles could be time to replace (the front one). Especially if it has a layer of char or mess on it.

I'd go back over connections on the exhaust to make sure there's no leaks, loosen and re-tighten. If there's no thumping or knocking sounds, may not be exhaust leak. I've had revs hang from a worn out clutch before too. Last thing would be vacuum leak. Hard to say whats goin on, could be 2 unrelated things.

The codes were "left bank running lean or bad 02 sensor connection" and "low 02 sensor voltage". I don't remember the exact codes. That's just what google told me.

I'll check the exhaust connections and zip tie the sensor this weekend. I'll report back.

Your help is very very appreciated, by the way.

 

[mja]

How many odometer miles?

Pull the O2 sensor and lightly scrape it with a key/screwdriver on the metal part, if there's a layer of crud, soak the metal portion in gasoline to clean it off. Soak overnight and wipe off the char with a rag or brush, If there's more crud still, brushing with gasoline or rubbing with WD40 should clean it up. Reinstall. Gasoline may melt a cheap plastic tupperware, tin or alum can will work.

Try some dielectric grease in the connector to get a good connection too, they sell them in little packs for like 50-99 cents at the counter of the auto parts stores. Use copper or some antiseize* on the threads to make it easier to remove the O2 sensor later, they sell these at the auto part counters in packs too.

Last thing is reset the ECU, unhook the battery overnight while the O2 sensor soaks, plenty of time to reset the computer. Drive it around for a few days or week and see if the codes come back.

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