2006 Lexus GS 300.
I recently changed my spark plugs out; I used the exact same Denso plugs and have my check engine light on, vsc off. There were no check engine lights on prior to the spark plug change.I did nothing other then change like for like plugs. I had a mechanic look over my work to make sure I did not miss anything. I unhooked the battery over night and when I reconnected the battery the check engine still will not clear. I hooked up the computer reader and it said B cam sensor. I bought two new cam sensors and installed them both, tried to reset the code and still check engine light. The computer would not let me reset it. So I unhooked the battery again. The car runs great since new plugs have been put in. I have driven about 400 miles on the new plugs.

I did not gap the spark plugs because they came already set, plus I read that you do not gap iridium plugs. I am so lost. I have gone over everything at least five times. Steak and beer to whoever helps me out.

I am ready to head to the dealer.

 

I literally had the EXACT same thing happen to me and i forgot to plug the cam sensor back in:

https://www.clublexus.com/forums/gs-...oday-pics.html

 

I checked four times and both cam sensors are plugged in correctly. Everything is like original. Thank you for the input I wish that was the problem.

 

Have you ever had your engine rebuilt because of carbon buildup?

06 gs300 are notorious for building carbon. I would take it to the dealer and pay an hours worth of diagnostic before I would drop money on parts and trying to guess whats wrong with the car.

 

I suppose it's possible that you had a dodgy harness lead from that sensor and when you disturbed it, it broke somewhere or just became disconnected somewhere else. Try to follow the harness to wherever it leads (may be difficult) and inspect the wiring all along. You may need to figure out where the sensor leads to the ECU and check that end with a multimeter to verify at least proper continuity.

At this point though the first thing I would probably try would be to return your old spark plugs back and return everything the way it was before you changed anything - you did keep your old parts right? (ALWAYS keep your old parts until you are absolutely sure that the new ones are working correctly)

 

This is so true...especially when nothing was wrong before the work...my dealership gets on my nerves at times but I don't have the time to chase down issues like this so I'm willing to pay the $200 to change those plugs...seems like that harness is very delicate...

 

Took the car into Lexus and a $228 fix was a lose wire on the cam sensor. Found broken wire at B1, exhaust cam sensor plug. Repair broken wire and retest system. They washed the car and the light came back on. So they reset again and no light.

Thank you for everyone's help.

 

Awesome glad they took care of it for you. $228 that not bad a whole lot better then dumping parts and chasing repairs.

 

Good to know! I am about to do my plugs on my 08 460 soon so def gotta be careful with those wires/harnesses

 

give us a DIY on your spark plugs whitevomr. i need mine done soon too. would appreciate any tips when you get yours done. thanks