02 sensor failing?

[Spaniel1287]

Ever since i bought my 95 Talon TSI the check engine light has been on. I took it to the mechanic and they hooked it up to the computer thing and over 10 times it said that the code was telling them that the o2 sensor is not right and is mailfunctioning. The mechanic told me it would cost $250 to replace and he told me that its not even worth the money. He told me to just leave it be. What do you guys think about this? If my o2 sensor is not working right could that cause problems in my engine and would i lose power or boost? Thanks

 

[blackGSX2g]

What code did he pull up? I would go to autozone to have them pulled if you don't have a logger. Its free and they give you the code number.

Hook a voltmeter up to your o2 sensor when its on and if volts bounce around from .01-.9 the sensor is fine. If it shows low voltage all the time then chances are it is dead. When mine went I got really bad gas mileage, so how does he think its not worth it to fix? Sensors are only around $100 and if you can unscrew the old one and put the new one in yourself, then you save labor costs and can have it done quickly.

Though a bad sensor may cause poor engine performance, it shouldnt' cause you to not have boost. When you go WOT, your engine goes to 'open loop' mode where it ignores the o2 sensor completely.

 

[Spaniel1287]

Yea well when i went out to the track my 95 Talon TSI ran a 16 flat 3 times in a row. I thoguht that sucked for my turbo car and the check engine light was on because of the o2 sensor there too. Yea I only usually get liek 230 miles to the tank. Where can i find a new o2 sensor? Yea my dad and I could take off the downpipe and just plug in a new o2 sensor but where cna i get one at?

 

[blackGSX2g]

Check the websites for Autozone and Advance Auto Parts. They all have online listings, prices, and availability from their sites. Some people only use OEM sensors, but I think the dealer wants around $120 for the part where as you can get it for about half as much elsewhere. I use a Bosch sensor and it works fine. Also, you don't need to take off the downpipe to get to the sensor, it is in the o2 housing right off of the turbo.

 

[JiveMasterT]

what can happen is that if your o2 sensor goes bad and your car starts running rich (my car is victim of this...) it will foul your plugs and when you do go under boost it wont pull like it used to. just something to think about.