Oxygen Sensor in 98 Ford Escort

I see most of the parts stores around me carry Bosch. Will I get into trouble using a non ford part here? - John

How do you know it is failing?

A lot of people recommend using on OEM replacements.

jeff

Are you sure it's the sensor? And if so, which one? (a '98 should have two, one upstream and one downstream of the catalytic converter). Oxygen sensors sometimes fail, but more often than not a 'lean' or 'rich' code from them just shows that they are doing their work and the problem is elsewhere.

Most often the O2 sensor is working and is just cluing you in to some other problem, possibly a vacuum leak. Parts stores always tell their customers to replace their O2 sensors because then they buy one immediately. When that doesn't work, they suggest something else. It's their business. Find the real problem and then go buy that part. Don't shoot the messenger. Have the car scanned for codes and post them here, you'll get some real help and direction.

I will get it scaned today at AutoZone...

John

I am glad my mechanic didn't change the O2 Sensors. Although, the car has

160000 miles on it. AutoZone checked the code and found P0442, evaporative container. They had me replace the gas cap. If its not that I can work from there. I did find the code on the web in a TSB. They have summaries of the problem but not the solutions. I suppose I can call the dealer.

Thanks for everyone's help. John

An improper sealing fuel cap can certainly cause that code, as can fueling the vehicle with the engine running. It's also very common, on mid-late 90s Escorts, for the Canister Purge Valve or the Canister Purge Sensor to fail. So common that it is recommended to replace them both if one is found to be bad. The 2 parts came together in a kit from Ford as late as '02 for sure. They may still be sold this way.

They still are, for about $70 for the kit, which includes the 2 parts and the hard tubing that connects them both. However, the code for that evap problem is usually P1443. A P0442 is more likely a small leak in the gas tank, filler neck or gas cap.

Thanks for the refresher Bob. I've been away since early 2001, many of those brain cells have gone to sleep. You're right, P1443 usually led to the Purge valve and/or sensor. P0442 was common if the gas cap was leaky, or there were other minor EVAP leaks.