O2 Sensor bank 2 cts Tail light stay on

[kthomas3]

Hi,
I have a CTS 2003 with 66893 miles. I notice a couple times when I step on the brakes and I release BOTH brake lights stay on. This happens even when I park and turn the car off. What can the problem be?

Second question:
I notice when my car is in idle i feel a small subtle tremble/vibration through out the car. feels like a small misfire. I have a check engine light on and the code told me it was my O2 sensor in bank 2. Can this be the reason why I feel that vibration? Also can this O2 sensor in bank 2 (after cat converter) affect my fuel efficiency/economy?

Thanks!

[Sammy Z]

Wecome to the forum. It was common to feel the shake in the 03 engine. I have the same problem and have sat in a few more and they all seem to do it. You should replace the bad O2 sensor, but I don't think it will fix the shaking. I think there is a mod for it where it raises the idle RPMs to 800 but I'd rather have the lower rpm and live with the shaking. I don't know if the new O2 will change the fuel economy, but you won't be able to pass an emision test with that problem. Good luck

[Sammy Z]

Originally Posted by kthomas3

Hi,
I have a CTS 2003 with 66893 miles. I notice a couple times when I step on the brakes and I release BOTH brake lights stay on. This happens even when I park and turn the car off. What can the problem be?

Thanks!

If all three brake lights are on, I'd say the problem is in the switch by the brake pedal. Take the cover off below the steering wheel and inspect the brake pedal and the switch. It may be as easy as spraying some silicone lube on the actuator. Try to do a search on this forum for brake light switch.

[MuGeN]

1- o2 sensor can afect your economy

2- reajust the brake light sensor on the brake pedal and should be ok.

[kthomas3]

You guys are amazing, seriously! I will work on it today and let you know the results. My next question is, where can i find the owners manual or repair manual for free to download ?

[Sammy Z]

I found this link ( below) but I don't know if they have all years there. If not, do a search on this forum. Also, some of the folks swear by the "helms" manual, but you'll have to do a search to find that as well.

http://www.cadillacforums.com/forums...anual-pdf.html

[kthomas3]

thanks. I just got back from the shop. Brake light problem fixed! When the code were ran this is what came up
Bank 1 sensor 1 - slow response
Bank 2 sensor 1 - malfunction
Bank 2 Sensor 2 - malfunction

Banks 2 sensor 2 was replaced today also. My question is, could sensor 2 bank 2 cause all the other sensor not work? The mechanic pulled the codes BEFORE the bank 2 sensor 2 was replaced.