Hey guys, really quick question,
I just bought a 99 Si, and the guy told me the check engine light came on, and he thought it was the IAT sensor, he cleaned it and it went of.. Ok, no biggie.. So it came on again a couple days after i bought it. Figuring it was the sensor worst case scenerio, $60 gets me a new one..
But my new theory is, I put 89 octane gas in it the first fill up.. Now this tank i put 91 in, and today my light went off.. Could it be it was detonating, and that set the light off? I dont know if thats how the sensor works but, my little theory because nothing else changed.. let me know!
TIA!

 

why don't you check to see what code it's throwing...

Search and you'll find out how to check the codes if you don't know.

 

yeah... well i will have to do that, but its raining out, and i dont want go out there, i was just wondering if knock and ping would light the check engine up, or if it just retards your timing and stuff without a light..

 

Pinging usually is due to octane issues and timing. With a B16, I'd only use 92/93/94, but that's just me. Try using high octane from now on and check if it goes away. How's your timing BTW? Have you messed with it?

 

no, i have only had the car for two weeks, and havent done anything to it.. I am going to keep using premium now and see if the light stays off.. I didnt notice the premium only thing right away, but i saw it this time

 

Most people use Premium octane on DOHC VTEC engines. Since those are the high performance engines, use Premium. Ping should go away.

 

Roger that, thanks man.. But will a ping set off the knock sensor, and could that be what the light was about? i mean, just take a guess.. because i dont know if that would cause a check engine light or not

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aphex23 &raquo;</TD></TR><TR><TD CLASS="quote">Roger that, thanks man.. But will a ping set off the knock sensor, and could that be what the light was about? i mean, just take a guess.. because i dont know if that would cause a check engine light or not </TD></TR></TABLE>

Should be. On OBD2+ cars, when there is a ping in the ignition system, the knock sensor is triggered and will give you a CEL.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dimitri_EG8 a.k.a. Dimi &raquo;</TD></TR><TR><TD CLASS="quote">

Should be. On OBD2+ cars, when there is a ping in the ignition system, the knock sensor is triggered and will give you a CEL. </TD></TR></TABLE>

yep, obd1's too. you get a cel, and retarded timing. it really slows the car down. get the code, it doesn't take long.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IHateJDM &raquo;</TD></TR><TR><TD CLASS="quote">

yep, obd1's too. you get a cel, and retarded timing. it really slows the car down. get the code, it doesn't take long.</TD></TR></TABLE>

What CEL would it give you if that were the case?

Most cars (non-honda) will just retard the timing and you will get reduced performace, but not a CEL. So if the Honda is setup to give a CEL for engine knock, what CEL would that be? I guess it could give a misfire code or something, but that could be caused by more than just detonation. like bad plugs or a messed up cylinder.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flood &raquo;</TD></TR><TR><TD CLASS="quote">

What CEL would it give you if that were the case? Im asking cause I dont believe you.
</TD></TR></TABLE>

23

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IHateJDM &raquo;</TD></TR><TR><TD CLASS="quote">

23</TD></TR></TABLE>

Thanks. Isn't that the same code you would get if you unplugged the knock sensor?

I know my D16Y8 has a knock sensor, but I thought it would just retard the timing and not iluminate a CEL. Interesting.

 

okay sweet, thanks a ton for the info guys premium from now on it is

 

yep, you can get it from actual detonation or bad/unplugged sensor. i've thrown it both ways on my obd1 h22.

 

usually on a obd2 car when you are detonating the cel will flash during the pinging/detonation. not turn on solid unless its a long term problem or an actual problem with the knock sensor/circuit.