ItsRocco

Hello,
I received check VSC, engine light, traction light combination immediately after filling up my tank with premium gas at Costco as I normally do. Error display started to appear 10 minutes after idling in parking lot. Engine started to hesitate, loss of power and temporary very low idle and rough idle when driving immediately afterwards. I tried to shut off car, remove gas cap, replace gas cap and turn until 1 click (I may have not turned gas cap to fully 1click position when fueling) and started car again. Took car to autozone immediately and ODB2 diagnostic read P0301- cylinder 1 misfire detected. P0201 injector circuit/open cyl 1 Also printed on report. 70,000 miles and out of warranty.

Could this error possibly be caused from water in gas from Costco premium gasoline? Or not fully tightening gas cap to full 1 click position. My car has never had an issue since I purchased 1.5 years ago. Vehicle history report shows no signs original owner had issues.

Will this go away on its own? Should I try adding dry gas to ensure if any water in the tank flushed through bottom of gas tank?
Idle and less hesitation seems much better after 20 miles of driving back home from auto-zone. How long should I wait to reset the ECU from a Lexus dealer or local auto technician? Will the error most likely reappear after resetting ?
Any assistance would greatly be appreciated.
Thank you

sktn77a

iTrader: (2)

I doubt this was caused by the gas cap. You could call costco and ask if they got any complaints on the date you had this problem. Could be dirt in the underground gas reservoir if it had been stirred up by a recent filling. But it sounds like an injector issue. Clear the code and see what happens. If it comes back:

"Begin by hooking up an advanced scanner to the DLC port and checking for codes. Any code present will generally have freeze frame data associated with it. This tells them under what conditions, such as vehicle speed, operating temperature, and engine load, the code occurred under.
The codes will then be cleared and the test driven to see if the code will come back or if it was a one-time occurrence. If the code comes back, a visual inspection will be performed on the injector circuit and fuel injector itself.
Next, the technician will check for voltage at the injector to confirm proper operation. A scan tool will be used to monitor injector operation and a noid light will be installed in the injector wiring to test for the correct pulses of the fuel injector.
If all of this checks out, a manufacture specific ECM test will be performed."

Good luck.

rstewart

I had the same issue and took it to my Lexus dealer. Their diagnoses was a faulty gas cap. They replaced the car gap and reset the error code. everything is fine now. I have a 2013 LS460 with about 52000 miles.

sktn77a

iTrader: (2)

I don't think you get the misfire and rough running with a gas cap error, just the CEL.

dfkd

I had the same symptoms on one occasion and it was simply that my gas cap wasn't tightened properly when I filled up.
Re-tightened it and cleared the code and I haven't seen an error since.
Didn't even need to replace it.

roadfrog

I agree with Keith. The error code is pretty specific - "Cylinder 1 misfire" and "cylinder 1 circuit". Sounds like a bad coil pack on cylinder 1. A bad fuel cap will emit a CEL but won't cause a misfire.

HewittTech

Like roadfrog says. You have an ignition coil that needs to be replaced. Trouble codes exist to point you in the right direction for a repair. Unless it is one of the evaporative emissions codes a gas cap has nothing to do with it.
It also does not benefit anyone on forum threads to say replacing your gas cap fixed the problem unless you also know/share the specific details of your problem like the Diagnostic Trouble Codes (DTCs) that are causing your CEL.