Atomic350F

Yeahp, if the o2 sensor was completely cut off your check engine light would be blaring at you!

I just noticed your signature mentioning some custom exhaust.. how long have you had the custom exhaust vs when this started happening?

I hope its not messing with your ecu... and hope they dont give you a hard time at the dealer about this either.

bigblack06

iTrader: (20)

Well I had this system on my 13 GS so nothing different and I had that for a while so I have no idea what it is. I'm hoping they don't either. Haven't heard anything all day so still nothing.

Atomic350F

Gotcha, I would think the ecu could compensate for the minor exhaust changes.

Glad to hear it's at the dealer already, good luck to you and you GS! Did ya get a loaner to beat on at least?!!

bigblack06

iTrader: (20)

Ok they reset the car, and it seems to be running fine now actually normal. It begs me to think that it could have been the vivid racing flash. Car is running great though now battery checked out fine.

Atomic350F

Reset the car as in the ecu I suppose you mean.

Guess that means any tweaks from the Vivid unit is gone now too huh. Sounds like that thing may have been more trouble than good in the end?

bigblack06

iTrader: (20)

Well no not the ECU they just unplugged the battery let a sit for a couple of hours and then put it back on not sure exactly what they accomplished but the car is no longer shaking. Vivid racing flash is still there I called to verify he said unless ECU is reset or I plug the Vivid racing module in thats the only way.

Atomic350F

Hmmm, well I’m not exactly sure about the 4GS but I know on cars I have had in the past, and older GS’s this was indeed how you reset the ecu (unplugging the battery)… maybe someone else can chime in to confirm?

So the Vivid unit is plugged in now and its running fine, better than stock would you say even due to the Vivid flash?

sgmstr

This happened to me a few times. Dealer diagnosed and nothing showed up. They told me to put a different brand gasoline. I've gone from Mobil to 76 and it hasn't happened since.

bigblack06

iTrader: (20)

No the flash is only used once to put in OBD port then take out.

I doubt its gas as I only use two types and I seem to rotate on them depending on how I feel. Shell, Sunoco

Afrosheen

Good to hear you got fixed up. I'd like to see an updated pic of your new gas mileage.

bigblack06

iTrader: (20)

Will take later but it was 15.6MPG city driving.

hypnotika

Congrats on becoming Forum Moderator bigblack...it's been awhile since I've been on but this is the EXACT issue I'm having. I brought it in to the dealership but I just cant replicate the problem. I also have a 13 GS but I live in Southern California so cold weather isn't really the culprit.

Times it happened to me: cold starts (in the morning or when starting car after 4 hours or so), sitting idle at a stop light, or placing the car in Park and just sitting idle. It happens now and then with RPM dipping around the sub 600 range...only problem is I can never replicate the issue and so the dealership could do nothing for me.

I'll ask to reset the ecu next time I go in for 30K. Please keep the thread updated if the issue comes back! The thing for me is it could be weeks in between when I notice the "Shivering / shaking" of the car in idle...

Afrosheen

Just reset the ECU yourself. Pull the terminal off the battery, wait 5 minutes, put it back on and start it up.

bigblack06

iTrader: (20)

Thanks. Yep sounds the same it seems to be coming back but not as worse as it was before as the car would shake now its just strange it revs high cause of cold then when it settles its so quiet that feels like car is gonna shut off that I think now is more because of exhaust as I don't have the shaking problem.


Yep that basically what they did.

Atomic350F

So if the ECU was reset, did that erase the Vivid flash or would that still apply?

And/Or did you reflash with the Vivid unit again after the dealer rest the ecu?

Just wondering if that Vivid unit may be causing any issues for you or if that has been ruled out...