low octane check engine light

I was at my local gas station and they didn't have the 91 octane gas. So I put in the mid grade at 89 octane. My check engine light came on? I pulled the code and it came up with "Lambda sensor detected weak fuel mixture". So do I need to add octane booster to balance out the octane? Is it safe to drive with low octane?

You can add octane booster but you may need a few bottles depending on how much fuel was filled.

 

Alternatively, you can look up a 98 or 100 octane station. Those run for $8-9/gal.

 

Lastly, you can just drive. The engine will make adjustment but you are better off not driving it hard.

Hi Djantlive,

 

Have this happen to your Diablo before? I did not realize that these cars are that sensitive to the octane? I filled it all the way up. So I will try to add as much octane booster as I can and see if that helps. Otherwise I will take out some fuel and add racing fuel.

You can add octane booster but you may need a few bottles depending on how much fuel was filled.

 

Alternatively, you can look up a 98 or 100 octane station. Those run for $8-9/gal.

 

Lastly, you can just drive. The engine will make adjustment but you are better off not driving it hard.

 

That's very interesting, 98 octane is available here at almost every station at a much lower rate than what you guys are paying, I always thought fuel is much cheaper in the states.

 

I would never consider putting 91 in my Lambos. Actually, I use 98 in every single car I own, regardless of what it is.

 

I'd add as much octane boost as possible. The engine will ping otherwise and have serious damage, won't it?

I've never run anything but 91, and I'm sure a lower octane could be used. Performance might be down, but that's what fuel injection and computers are for, as was stated it will make adjustments to deal with it. ie. won't ping. I think running more octane than necessary is just a waste of money. I'm more concerned about running ethanol over 100% gas.

That's very interesting, 98 octane is available here at almost every station at a much lower rate than what you guys are paying, I always thought fuel is much cheaper in the states.

AKI vs. RON. Our 94 is your 98. 93 is available at every station for under $3 a gallon right now. Cali only gets 91 and below at most stations.

You guys outside of US use a different octane rating than in the US. in Asia and Europe, the octane for premium is 98 where as that's 93 or 91 in US.

 

It may be possible the light isn't related to ur fuel. Do you ever get that light before?

Thank you guys.

You guys outside of US use a different octane rating than in the US. in Asia and Europe, the octane for premium is 98 where as that's 93 or 91 in US.

 

It may be possible the light isn't related to ur fuel. Do you ever get that light before?

 

This is the first time the L & R check engine light have ever came on? I have not had a chance to take some gas out and put in octane booster or racing fuel. I don't want to chance driving the car and cause any damage. So I will have to wait until I have a free weekend to take some gas out. I have always put 91 octane. This is the first time putting anything lower and the check engines came on. It was interesting that there is a code for lower fuel mixture? Thank you all for your reply. I will keep you posted if it is in fact the low octane that caused the check engine light to come on.

I was at my local gas station and they didn't have the 91 octane gas. So I put in the mid grade at 89 octane. My check engine light came on? I pulled the code and it came up with "Lambda sensor detected weak fuel mixture". So do I need to add octane booster to balance out the octane? Is it safe to drive with low octane?

 

There is no such thing is a low octane cel. Weak fuel mixture means the air/fuel mixture is off or out of adjustment. Never seen this on a fuel injected motor.

 

Could be O2 sensors going bad. Just add in octane booster and run it.

Could be O2 sensors going bad. Just add in octane booster and run it.

 

Agree. The ECM is probably taking its measurement at the O2.