[AKSteve]

Is there any chance the warmer summer temperatures are causing the sudden increase in CEL problems with people who have tuned their cars with the JB3 setup? I think I read somewhere that tuned cars need higher octane levels when the ambient temperature is hot. I was thinking of maybe just using the stock JB3 boost setting for the summer as the octane level in premium gas up here is only 90.

The only problem I've ever encountered is that my car's idle sometimes stumbles, but it does this whether the JB3 is installed or not. I was wondering if the fact I've been using octane booster for a while might have fouled my spark plugs? I've stopped using it, btw.

[oldrandomguy]

Its been 60 outside every day... No.

[D.B.S]

Originally Posted by AKSteve

Is there any chance the warmer summer temperatures are causing the sudden increase in CEL problems with people who have tuned their cars with the JB3 setup? I think I read somewhere that tuned cars need higher octane levels when the ambient temperature is hot. I was thinking of maybe just using the stock JB3 boost setting for the summer as the octane level in premium gas up here is only 90.

First I've heard of it... I've been running the JB3 in my X5 since Nov '10 and with the latest Firmware update back in March 11 only CEL i've had is due to my FMIC connection hose coming off. I do use 93 octane though.

Originally Posted by AKSteve

The only problem I've ever encountered is that my car's idle sometimes stumbles, but it does this whether the JB3 is installed or not. I was wondering if the fact I've been using octane booster for a while might have fouled my spark plugs? I've stopped using it, btw.

I don't think so... I've not used any octane boosters in mine and this happens on mine as well (idle stumbles with JB3 installed or removed). The octane boosters aren't causing this... Its something else, what? IDK...