haacer

iTrader: (1)

I figured out that the code setting in my 95 A4 is due to the wrong (OBDII) knock sensor. I haven't had a chance to change it just yet and I'm wondering...what is going on when the knock sensor code is set? Is max timing retard being set? How much of a difference in power can I expect?

infinitebird

iTrader: (11)

Yes it's essentially the max amount all the time. You will lose a great deal of power and it will run poorly.

The knock sensor is cheap, like $25 max. Just swap it out.

haacer

iTrader: (1)

Wow...

I bought the car with a broken transmission. The previous owner put every bolt-on item he could think of and some random cam. It broke the stock transmission on the second track run. He drove it with that knock sensor for almost a year.

With that sensor, the car ran 13s.......................

I need to get that transmission replaced.

Thanks

infinitebird

iTrader: (11)

yeah, 13s with cam and full boltons isn't exactly hauling

haacer

iTrader: (1)

Absolutely... I'm just thinking that if it went 13s with full retard, when it's running right it should be significantly faster...

How fast would you expect with full bolt ons?

Razor_Blade

iTrader: (8)

I don't have time to go into detail, but I made a 1/4 mile pass with by car pulling max timing. I gained 7 tenths and lost 9 mph on that pass, or maybe it was 9 tenths and seven mph. Anyway, it was a significant amount of performance that was lost.

The Engineer

You should swap-out the factory LT1 PCM knock-module with an LT-4 knock-module. The LT-4 knock module will greatly improve the spark-retard issues. Check out this link.

http://www.projecttransam.com/projects1.asp

WD

infinitebird

iTrader: (11)

While this is a good idea, it will not fix his problem.

The knock sensor is different on OBD1 and OBD2, if the wrong sensor is used, the computer sets code 43 which means it cannot get a reading from the knock sensor.

The knock module is only utilized after the signal from the sensor is sent to the PCM. If the signal from the sensor is faulty, the knock module used is irrelevant, it will still pull the max timing. The knock sensor and module are sometimes confused. The module is what is inside the pcm, the sensor is located on the block on the lower right side.

The Engineer

The LT-4 knock module "filters out" a band of frequencies from the knock sensor that can cause the PCM to retard the timing. Yes, depending of the year model (ODBI or ODBII), the sensors are different.

PCM tuning is probably the most effective tool, however, the knock module in the PCM is also a factor.

WD

Formula350

iTrader: (3)

Instead of making another thread, I figured I'll ask my dumb question here. Sometimes in WoT I get pinging, but doesn't seem to pull any knock retard. So could I sit with my scanner next to me (I have a cool hand held that gives live sensor readings) and then just lightly tap the knock sensor with say a screwdriver handle, and see if it pulls any timing? I don't have any codes being thrown, but I just am wondering if it's either working right, or at all

sbs

iTrader: (1)

Neither has any relevance to the OP who has the wrong KS for his PCM.

infinitebird

iTrader: (11)

If you do this you want to tap on the block, not the sensor.

haacer

iTrader: (1)

I haven't done this before...but it seems to me that it would be just a little hazardous to tap on the block near the sensor with the car running... Is this something you could do with ignition on, engine off?