Local non-dealer replaced Mass Air Flw meter with first Engine Light...then 2nd engine light they replaced Oxy Sensor and Sensor cable. NOW ,,,, light is on again month and half later. They ding me $95 for diagnostic each time. Do ya think all is kosher by going back again???

Doug

 

Hi Doug: The best thing for you to do is get yourself a OBD-II scanner unless you NEVER plan on fixing your car yourself. A lot of people can get their cars scanned at places like AutoZone, O'Reiley's, etc., you can try that.

Please remember that you have a 13 year old car that will need maintenance and repairs all the time. My estimate is that your car will cost you $75 per month, that being said, how much have you put into the car over the past 12-24 months? Tires, oil changes, diagostic fees, etc. Most mechanics will credit a diagnostic fee towards the repair, if the repair is done within 30 days.

 

Thanks for overview..yes I bought scanner. Shows O2 sensor . Mechanic who previous ly replaced both sensors says return car; sensors have to "...re-learn" the program (???) Fact???

 

A month in a half later is a long time to learn. I think they usually learn in about 400 miles. I guess I would ask if it was replaced with an oem sensor? If not, you need to get the oem sensors, IMO. I cleared my codes right after I replaced the sensor and never got a CEL again.

 

[QUOTE=rspi;288772]A month in a half later is a long time to learn. I think they usually learn in about 400 miles. I guess I would ask if it was replaced with an oem sensor? If not, you need to get the oem sensors, IMO. I cleared my codes rightafter I replaced the sensor and never got a CEL again.[/QUOTE

Finished 800 mile road trip and lite stayed on; used scanner and turned off. Stays off now. You've been very thorough. Much. Appreciated. Doug

 

[QUOTE=osage;288865]Lite on again; I will ask mechanic if they used oem sensor. Code indicates sensor.

 

What do you mean when you say it takes around 400 miles to "learn"? Not that that is my problem..

I have a '99 V70 GLT that was diagnosed to need a rear O2 sensor and a purge control valve. I bought a Bosch O2 sensor for $30 online and put it in, wiring seemed exactly the same. I also disconnected the battery at the same time to reset the check engine light. And it seemed to run fine for a week (i dont drive much, <100 miles) before the light came back on and it started sputtering and puffing black smoke again.

Then I disconnected the battery again to see what would happen, and after doing that it runs pretty normal again.

Is it a safe assumption that i would just need to install the OEM sensor? The Bosche one doesn't work?

 

Volvo dealer gave me 3 possibilities after rear sensor replaced by a local mechanic and light still comes on: 1) faulty sensor--use OEM...2) vacuum disconnect 3) thermostat may need replacing.

Doug