P2191?

[Tin]

Couple weeks ago, the check engine light went on. I took it in and have the dealership check and they said that it was due to bad gas. We normally fill up with 89 gas at shell. So the last 2 weeks, we've been filling it with 91. At this time, we noticed that the car takes longer to start, along with once or twice where it shake really hard and the RPM went up past 2k. I cleared the code, yesterday. Today, the check engine light came back on again. We already put another tank of gas in it. Wouldn't the bad gas already gone by now?

2010 4.6 with 52k miles

 

[Mark_888]

Couple weeks ago, the check engine light went on. I took it in and have the dealership check and they said that it was due to bad gas. We normally fill up with 89 gas at shell. So the last 2 weeks, we've been filling it with 91. At this time, we noticed that the car takes longer to start, along with once or twice where it shake really hard and the RPM went up past 2k. I cleared the code, yesterday. Today, the check engine light came back on again. We already put another tank of gas in it. Wouldn't the bad gas already gone by now?

2010 4.6 with 52k miles

Depends on how bad the gas was. If it had moisture in the gas, then it could still be there. On the other hand, just because dealer blames on it bad gas does not make it true. Take it back and tell them you got a new tank of gas (hopefully at a different station) and if the check engine light comes on make them fix it.

 

[JasTheAce]

I'd also suggest trying a different station. If a station has fouled 89, I'd imagine the 91 isn't much better.

 

[NSXNEXT]

I would throw a can of Seafoam into a full tank of gas and really open the car up on the highway.

 

[Tin]

the car shook and vibrate again this morning, follow by a burnt smell coming out from the car. We took it out on the highway last weekend and let it burn some fuel. we are going to empty out this tank and fill it up at a diff station.

 

[EXBMWGUY]

I'd bet a nice lunch you have one or more injectors that needs to be replaced, so the fresh gas you put in now might not do much good.

Chevron with Techron is a good fuel system cleaner, but won't help an injector that has been ruined by bad gas (bad being more than just some water). Seafoam was a safer bet on cars a few years ago than it is today with modern fuel pumps and more precise design and calibration o. everything. I was told that using it will void a fuel system/emission system of a BMW. On the other hand, I've used Seafoam very successfully with in the fuel tanks and crankcase of a few older cars.

 

[Mark_888]

the car shook and vibrate again this morning, follow by a burnt smell coming out from the car. We took it out on the highway last weekend and let it burn some fuel. we are going to empty out this tank and fill it up at a diff station.

I assume you know that a fair number of people have reported problems like you described at start-up. This is usually caused by the engine being run for a very short time, shut off, and then later restarted, and some engine components are in the wrong position at startup. Most do not suffer permanent damage from this, but a few had such severe damage that they needed (and got) an engine replacement. Don't let the dealer push you around with BS about bad gas.

 

[10genesis]

2 years ago I had the same problem with my 4.6. The service manager gave me the same spiel, it was a load of BS. Dealers have been using that "BAD GAS" crap for decades.
25 years ago I had a friend that was a service mgr at a chevy dealership, he had a collection of baby food jars with gas that he put dirt in and told customers they needed to have the fuel system removed and cleaned at their expense. Anyway It boiled down to that my Genny had a bad electric fuel pump. They replaced it under warranty and I have not had a problem since.

 

[Tin]

I brought to another dealership. I told them that 10Genesis has a similar issue and to test the fuel pump. They came back an hour later and told me in fact it was the fuel pump. They asked if I want to take the car back or get a loaner since our car is getting such a bad gas mileage. We got a brand new Genesis to drive around.