I brought my car to the shop for a possible faulty rear oxygen sensor and was quoted $969 to fix it. They said that when replacing the rear oxygen sensor there's a 50/50 chance that the threads on the catalytic converter would get messed up causing it to have to be replaced also. There is nothing actually wrong with the catalytic converter right now though. This sounds strange to me. Is it actually possible to ruin the cat by just replacing the O2 sensor or is the shop trying to screw me over?
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1999 Saturn SL2 Question: rear oxygen sensor
Answer #1hemicuda May 26, 2011, 11:34Master
Best thing to do is get another opinion from a different shop and you can locate a shop near you here www.repairpal.com/directory
Answer #2Visitor, May 26, 2011, 23:02
O2 sensors can seize and damage threads but can often be repaired with the proper tap. Often a rear O2 code is set due to a nonworking cat convertor, but it could also be a failed sensor. A little more diagnosis is needed here before jumping to any conclusions.
Replyddavi75, May 26, 2011, 23:29Rookie
the shop actually said it was the O2 sensor so I wasn't jumping to conclusions rather just questioning why a properly working catalytic converter(also their diagnosis) would need replacing since that sounded strange.
Replyhemicuda, May 27, 2011, 12:43Master
Thats why I recommend to get another opinion
Answer #3Visitor, May 30, 2011, 18:27
A cold oxygen sensor is extreamly tight in the threaded area and can tear threads when being removed. Sometimes minimal damage. To avoid any kind of damage it is best to apply a shot of Liquid Wrench, WD-40 or similar lubricants while the sensor thread area is cold (or cool) then start the vehicle and allow the sensor to get hot and while avoiding a burn to the hands you can turn the sensor out without any trouble. This has worked many times for me. HEAT HELPS
boston2013 January 04, 2013, 14:18Rookie
hi they definelly trying to screw you, for those having this problem with oxygen sensor,first check under of dash driver side and or under of the hood for a fuse box,there is a fuse with letter htr or fi htr its probably blow if so switch it hope helps thanks