Driving home around 11pm CEL came on...@ 59,300 miles going to autozone in the morn or something to get em pulled... nm, just a p0546
P0546 Exhaust gas temperature sensor circuit high input Did you put your uppipe in? you could have bent the egt probe in the process.
My 04 did this removing the second cat in the upipe causes this code to come about. the only way around it is to get tuned and have it shut off. If it was a p0420 that is much easier to deal with just see what Scott posted on the (boost creep or what )thread.
I got this or a very similar CEL one time on a long trip with an agressive gas additive.....I also had an aftermarket up-pipe as well....random tech....and I cleared it and it never came back again?....:wiggle:
Sometimes it can be a rich mixture or a lean mixture or just a flook mine did it a few time but it was a wiring problem...lol...i say clear it out and go for a ride and see if it comes back. oh yea mine also did it on Realllllly cold mornings if i got on the interstate and got up to speed a little quicker then usual onramp driving it would kick on.
it will clear itself out if the sensor gives an ok signal long enough. I forget how many miles have to go by, but its part of the OBDII spec.. even if it doesnt go away, its not hurting the engine operation, is it?
If you have a catless up-pipe you just need to unplug the egt sensor and put in a 2.2k ohm resistor and the code will never return. The egt is only used to measure the precatalyst temp so if there IS no cat the sensor is useless anyway! Mine's been this way for about 2 years, no problems.
i'm no mechanic or engineer. Does this Sensor actually affect how the engine runs at all? and will it hurt anything if left as is? <----no money...
no it doesn't do crap. just buy the resistor and plug it into the wiring harness under your solenoid cover. you can get a set of 5 resistors for about $1
i think so depending on the maps that come with the AP. Unless you get it pro tuned and they will shut it off!
The only crap it does do is read pre-cat temp in case of over heating, generally caused by misfire, whch would put the ECU in fail-safe or limp-in mode.So basically, without the pre-cat it "doesn't do crap, just buy the resistor..."
Unless you reset the ecu, the light went off but the code is still stored. If you are getting emission tested anytime soon you will still fail. I'd reset the ecu and see if it comes back after that.