QuestionThanks, Steve,
Any tricks to cleaning an O2 sensor? and if I've got 135,000 miles on them would it be reasonable to just replace them (I'm told they're around $100 apiece) or should I wait for them to fail again and then replace them (the reason I ask is because they're apparently spendy and I wouldn't think that they would or could foul the new catalytic converters, but I don't know)
Rod -------------------------
Followup To
Question -
After failing DEQ, I had a diagnostic run on my catalytic converters and found a bad reading (different temperatures at each end) on the driver's side cat. After lots of questions, I still have the following ones:
1) Should you customarily replace both cats when you do one? I have 135,000 miles on the vehicle and have been told that if you replace one, you'll be in soon to replace the other because of "differing stresses" placed on the remaining cat when you put a new one on.
2) Should you customarily replace both oxygen sensors when you replace a cat? What's the life expectancy of an 02 sensor? Can you clean an 02 sensor to get more service from it if it's one that has been on a faulty cat?
3) I can get the following cat for about $205 on the Internet. Is this a good thing or a not so good thing?:
"These parts are brand new converters manufactured by a company named Catco. They have a 5 year 50,000 warranty on workmanship and a 2 year guarantee on passing emissions testing in your area."
4) I have been told to use only Bosch or Ford 02 sensors when replacing them. Yes? No?
Thank you for your help.
Answer -
Rod-
Since you asked the questions in order, I'll answer them accordingly:
1. Yes...generally both cats are replaced since differing exhaust pulses *can* (but don't always) damage the older one since it doesn't flow the same as the new one.
2. The O2 sensors don't necessarily need to be replaced with the cats. They can't be cleaned really and there really isn't a set life expectancy on them...I've seen some go after 10K miles and some last for 100K miles.
3. The price you listed isn't too bad for a good converter. I've seen them cheaper but I've certainly seen them more expensive. And if it's got a 2 year guarantee on passing emissions then that's all the better should something cause them to clog.
4. Bosch sensors...Ford sensors...same thing. Bosch makes Ford's O2 sensors, they're just repackaged and renamed for use on Ford cars. They're both made the exact same way. As far as using other manufacturers...I personally wouldn't but that's not to say others don't make quality products.
Hope this helps.
Steve
AnswerRod-
Like I said, you can't really clean an O2 sensors. They fail because of their internal parts...not because they become clogged or covered in carbon build-up. I'd replace them with the cats since they're probably on their way out anyway. As for costing $100...I wouldn't be suprised if a shop quoted you that for each part. That's actually about double what they cost to buy yourself. You can find some good price at the following link (just copy and paste into your browser): http://www.oxygensensorwholesale.com/mercury_1997_grand-marquis.html The two top ones are the ones you'll want...and for a little over $50 each. Hope this helps.
Steve
