i got a dynotune today and the car did like 316/315 with a 355 forged 236/242 cam with full bolt ons and a cutout, and a 3200 stall.

i had a code which was 43 the knock sensor.

I was told that if replaced i could see up to 20hp.

Could this knock sensor be holding alot of my power back?

also i have a LT4 KM and for some reason the tuner never hooked up a wideband to my car

i paid 400$ expecting to see around 330/350 but came up very short. It was not a mustang dyno nither.

Should he have hooked up a wideband to make sure the a/f was good?

 

When a 43 sets, the PCM will retard timing. You will see a noticable lack of power.

Do you still have the original 95 knock sensor? Your problem may be an incompatibility between the LT4 knock module which is OBDII based and the original 95 knock sensor which is OBDI based. OBDI KS's have a resistance between 3.3K to 4.5K ohms. The OBDII KS will have a resistance between 93K to 107K ohms.

Normally a "tuning" run on a dyno would consist of monitoring A/F ratio. Did the "tuner" know you had a SES light set prior to running? Perhaps he knew it would make no difference what he did with the fault code already set. It would seem that he could have removed the knock monitoring from the programming, told you what it was really capable of and then put it back in. It appears from what you described that he never did any sort of "tuning". The car was only run and print outs made. You can speculate what he did or should have done but $400 is a bit steep for just running without any sort of programming done on his part. But then we don't know how he was charging you and how long you were actually tieing him/machine up.

 

Yeah, how can you tune a car without taking any wideband readings? Sounds like he didn't know what he was doing. I would find out what he really did.

 

The LT4 knock module does NOT need to be fed by the 100Kohm OBD-II knock sensor. By the time the signal reaches the knock module, it is simply a variable frequency riding on a carrier voltage, and the module is simply a filter. The LT4 KM works PERFECLTY with the 4.5Kohm OBD-I knock sensor. I verified that 8 years ago when I installed an LT4 KM in my 94.

 

i have a LT4 KM but its in my OBD1, not 2.

Im about to replace the LT1 knock sensor!

yea he didnt take a wideband which is odd.

But he was hoping to get at least 10-11 pulls and we only made 3 cause the shop closed down. Im going back tom.

 

No offense but I hope you didn't charged for anything more than 3 pulls. They should have stopped tuning when the DTC 43 was set. On top of that tuning on the dyno is pretty pointless without a wideband.

That is a professional opinion.. Take it how you'd like it.

 

actually i talked to him and im getting the wideband tom. Just have to weld in a bung. and replace my knock sensor!

No i havelife time tune. We didnt get to make alot of pulls cause the shop was closing.

 

ok replaced the knock sensor. SES went away, but came back after a while ONLY at idle. not all the time, but some times it would come on. but when driving it goes away. ODD huh?

any ideas?

 

no one?

 

And you verified the SES light is still for DTC 43?

 

im going to have it checked out possibly today.

But im not understanding DTC?

 

aww ok..

well when he ran the scanner he only came up with code 43. Fixed that and now another possible code is comming on?

cause of the ses light only at idle and not at driving