I have a 2003 LS V8 with 96000 miles. I just had the coils and plugs replaced under warranty about 3000 miles ago. I have about 1/4 tank of fuel left. My check ebgine light is on and has been for about 4 days and the code indicated bad O2 sensor left side down draft. I will be replacing that this weekend. However on my way to work today I noticed that the car has a shutter to it. It seems to happen when about 60 mph in 5th around 2000rpm. I have 2 questions, would a bad O2 sensor cause this to happen? If not, and ideas on what it might be? By the way, no other codes popped up when pulled the other day. Please Help!
O2 sensor and car shutter question
- Thread starter mep32jep
- Start date
zintkala
Active LVC Member
Take it back to the dealer and have them data log it. Ask to have the tech ride along with YOU driving; He/she will plug a laptop into the OBD II port and will be able to monitor all of the cars functions real time. The stutter is probably a bad coil, but could be other things. How long did you drive the car on bad coils before you had them replaced? You should just go ahead and do all of the O2 sensors, with those miles they will all be failing soon and you may have plugged cats which can also trigger a faulty downstream O2 sensor code. Quickest and most efficient way to figure it all out is to go back to the dealer. Good Luck
I had to drive it for 2 days while they ordered parts. Service tech stated this would be OK. They also told me that if the coils failed again the extended warranty on the coils would not cover it. Seems unfair seeing how I have only driven about 3000 miles with the new ones
zintkala
Active LVC Member
Maybe I should rephrase my first question. Your coils would have been causing a stutter or lumpy idle for a while before failing completely. Rarely do they simply fail, the question would be how long it was like that before it was bad enough to throw a code?
joegr
Dedicated LVC Member
I don't think that the downstream 02 sensors have any affect on the running of the engine. They are just there to verify that the cats are working correctly. Instead of 02 sensor failure, you may have cats that are failing. If they are clogging up, it could explain the shutter, or you may have more coils that are marginal that they missed.
I didn't read anything in the extended coil warranty that implied this to be a one time fix. As I read it, they should continue to replace any failing coils until the car hits 100K miles or 10 years.
There is a clause in R07M07 that says that related damage should be covered too. This means if the cats are failing due to the coil failures, replacement of the cats should be covered.
I didn't read anything in the extended coil warranty that implied this to be a one time fix. As I read it, they should continue to replace any failing coils until the car hits 100K miles or 10 years.
There is a clause in R07M07 that says that related damage should be covered too. This means if the cats are failing due to the coil failures, replacement of the cats should be covered.
joegr
Dedicated LVC Member
I think they check it by measuring the exhaust back pressure.
joegr
Dedicated LVC Member
EGR valve problems can.
my EGR valve went bad on my Nissan about a month ago, when I was accelerating it would buck (not consistently bucking but just buck once like a tranny slip or something) the autozone guy cleared the code and it took a few days for it to come back on.
joegr
Dedicated LVC Member
Yes, with many marginal conditions it is possible for the check engine light to come and go. Do be aware that codes for EGR problems could be caused by the EGR valve, clogged passages and tubes, and by faulty flow sensors. Don't just assume it is the valve. I don't know if excess exhaust back pressure could trigger an EGR code, but I have never heard of it doing so.
WINSTON
Active LVC Member
What was the code? My CEL came on and the code pulled related to "left bank lean" - which can be caused by the EGR valve.
No problems with the performance so I have left it alone. It has been about 3 weeks with the CEL on and yesterday it went off. Performance still seems fine, so I will leave it alone for now.....:shifty:
I do not remember the exact code. One of the codes indicated driver side dow stream O2 sensor bad. I went ahead and bought O2 sensors b/c of the mileage and will be replacing this weekend. The second code was something like EGR valve not reading or something like that. If the light comes back on, I will go to a different Adv. store and get the codes and write them down this time. Once again, I appreciate everyones help.