Ok so I got my DHP and had it in for about a week and everythings been great! But the other day, I was in a hurry to get somewhere, and I accidentally put about $10 of 89 octane gas into my very empty tank. I did highway driving, and later on had my SES light come on. I can't get ahold of a scanner, but after I got back, I only had about less than a quarter tank of gas left, so I filled it up completely with 93 octane to try to dillute (sp) the 89. Anyways, my question is, if you run too low of an octane with the DHP, will it trip the SES light, or is it probably some other problem??

Side note: I did this on saturday and now today (monday) the light is now off. Just curious..

Mmmm I don't know but maybe that's why mine is on? I pulled mine out

See what code it's thorwing. I was putting out a P0135 code which is a heater curicut code. Shouldn't have anything to do with fuel

if i run anything less than 93 mine clatters like hell, dhp changes the timing settings and knock sensors settings.

dhp v1.0 pcms do not change knock sensor settings on how its see's knock. it changes on how fast the KR recovers back to zero. and in all honesty, your talking thousandths of a second from stock settings.

and you can run 87 octane as long as you dont see any KR, your fine running a lower grade of fuel in your non boosted setup. without going to deep into this, basically the reason why dhp says to use higher octane is due to the KR factor. if you do not have KR with 89 octane, there is absolutely no point to go to 92+ octane.


my bet is that you didnt tighten your gas cap down all the way and threw a code, its happens a LOT.

however, if you got BAD gas, it wouldnt have mattered if its 87 or 103, bad gas is bad gas.

Thanks for the help, guess I just need to get it scanned to know for sure, But like I said, the light went out so I'm not too conserned....(as long as it stays out)

thats why i said i think it was from the gas cap not being tightened.


the code is stored in your pcm even though your light is not on. i would still go to a place and have the code read, just in case.

so if the gas cap isnt on all the way it throws a code? wierd....


what about when you leave your car running and fill it up at the station?

^it takes a certain amount of time before it will throw the "gas cap code"....which cost me 85 dollars to find that one out at a dealership back when i had my intrigue

yea, that gas cap code is a sneaky one, lol. that was the very first code i had on this car.

if i remember right, you have to have the gas cap click 5-7 times for it to be completly seated or some crazy crap like that.

ever since then, i get it about 15 clicks to be sure, lol.

Ok, just got a scan. P0172 : System too rich (bank 1)
I had this issue too after I got my headers on. I replaced the front O2 sensor. after my headers were put on. I just don't get it. This might explain why I struggle to break 200 miles on a tank of gas ??

maybe your not getting enough ait in the motor, and its just dumping fuel?

just throwing idea's

have you changed your plugs recently? if you did, did you notice any particular looking a lot different than the others?

theres a few things that could cause a rich condition like that, barring that the pcm is not toast or aftermarket...

injector could be stuck open
fuel pressure reg could be shot
fuel pump could be on the fritz, unlikely but possible
some other sensor is malfunctioning causing the pcm to think something is going on when its not.

its a good possibility your new o2 sensor is bad. not sure what brand you got, but i would only use a/c delco brand o2 sensors.

make sure not to touch the tip of the o2 sensor.

other sensors to look at is that AIT, TPS, MAF, MAP, and even a bad ECT could cause you to run rich/lean

you will probably want to get your hands on a multi meter and test things out.

Jeez, theres so many possibilitys. I guess it would be easiest to swap out the O2 sensor. Its a Bosch. I got it from my work (auto parts store) so I know I'll be able to get a free replacement under warranty.

:eek:

i had that problem.........i filled with with the low one on accident and it set off my ses light, after i ran it through and filled up with a gallon it turned off........

a lot of stores scan for free. like auto zone. i had them scan my alero so many times. lol that gas cap one freaked me out when it happened to me