Tonytoonz

...So a couple Mobil Gas stations near me have a new "formula" in their Premium (93) fuels.

This new formula was changed in beggining of July. (At least in my area) and it is causing my check engine light to come on.

-Check engine code is P2097 which says (Post Catalyst Fuel trim system too rich)

I feel no power difference but i do have more of a backfire when letting off gas pedal,as the rpms go back down.

Has anyone else experienced this with mobil fuel or any other fuels? Kind of worrys me that it might be causing damage to my motor, what would you guys do? Would you guys be concerned? How do you guys feel about this.

Dont really wanna use any other fuel other than Mobil. Its been so good to me besides this...

ygmn

could be O2 sensor or exhaust leak just near O2 sensor

Or fuel is contaminated so are you going to the same Mobil Gas Station?

Maybe try SHELL or Anothe Name brand Premium fuel...

Tonytoonz

Not 02 sensor or a leak.
Its the new mobil fuel for sure..i tried another mobil gas station without the new formula and check engine light comes off. Check engine light doesnt come on with Shell VPower either.
Went back to that mobil and comes right back on aftwr filling up. Pissing me off lol

G_Money

Shell VPower for the win

mrmotoguzzi00

Did a unknowing experiment with the bikes... i have a 2004 harley, my local gas station not a mobil, buddy with same year harley aka same engine, mobil is down the street and he always fills up there... after about 20k miles his bike is running pretty crappy... we tear it down and plugs and valves have all kinds of deposits... my local tuner confirmed the same thing... Mobil oil is great, the gas sucks.

skratch77

Says its supposed to clean out deposits alot better. Maybe your engine is junked up badly and it's coming out the back end.

Tonytoonz

Doubt it brother. Car feels good. And its just those couple gas stations that do that. Has to be something with tune/fuel/air mixture.

Diabolis

https://csnews.com/exxonmobil-unveil...l-formula-date

zcct04

Looks like we may be seeing similar fuel changes from other suppliers.

The link Diabolis posted above says that Exxon-Mobil's new "Synergy Supreme+" has additive package that includes two new ingredients:

1. A new friction modifier that reduces wear and tear on engines by 30 percent; and
2. An enhanced detergent package that removes deposits left behind [by lower quality gasoline].

https://csnews.com/shell-launches-it...d-premium-fuel says that Shell's latest premium gasoline, Shell V-Power NiTRO+, was introduced across the United States on May 20.

"The new formulation is engineered with four levels of defense against gunk, wear, corrosion and now friction to help keep engines running like new. According to the company, it is the brand's most advanced fuel and the result of more than a century of Shell fuels innovation."

zcct04

Mobil's new gas was just introduced a month ago. Unless your buddy has put 20k miles on his bike in the last four weeks, what the OP is seeing is different from what your Harley buddy experienced.

skratch77

I just put this gas in my car for the first time and I'm sticking to it from now on.

Noticed about 10% better throttle responce and the mid range feels really meaty and the pops and bangs are there.

Car is hitting 25 degrees on the cams on my race map and no other pump gas has done this. The most I would get is 20-23.

On ms100/109 I see 29 degrees on the cam profiles.

Put it simple this gas is amazing and not sure what's up with ops car