Tootall

iTrader: (78)

I'm tuning a 98 Formula with a cat back and LS1 intake. When the car was brought to me, it had a 4* of KR at 3800 under WOT. The car was not tuned for the intake, and it had a de-screened MAF.

I've tuned it with the STFTs. The table seems close but way off from the stock LS1 intake table. I still have 4* from 3800 and up it seems. What am I missing/skipping?

the first two are the stock tune/log . . . and the second is the modded tune.

I've pulled 3* on the low table, and it now has a screened MAF.

EDIT: Car now has a LS6 intake, and not the stock LS1 intake.

foff667

iTrader: (2)

If you have a descreened maf theres a good chance you'll need to tune the maf as well unless your running in SD mode only.

Tootall

iTrader: (78)

we've already swapped that out for a screened MAF . . . it's in my first post at the end. Thanks for the suggestion, but is there anything else . . . does the VE table look ok ?

foff667

iTrader: (2)

For just a car with a catback?(LS1 intake comes stock on a 98 LS1) no the VE table looks a good bit high IMO.

Tootall

iTrader: (78)

The owner installed the LS6 intake him self. Any ideas on the KR ? I've already pulled 3 across the board, should I try just that area of where it knocks ?

Tootall

iTrader: (78)

one more quick question. Can I pull the drivers side O2 sensor, and plug in my WB and use that port? Can I saftly tune with just one O2 on the PCM ?

foff667

iTrader: (2)

You said "I'm tuning a 98 Formula with a cat back and LS1 intake" in your initial post.

As for KR 98's are infamous for throwing 4* of false knock retard, you could probably pull out 15* & it would still pull 4*.

Im sure there are threads on here about it.

Tootall

iTrader: (78)

Hey I'm sorry about that, I'll edit the post above.

ok, thanks for the help, I'll keep searching.

E V I L

iTrader: (6)

Darn for some reason I can not see the graphs above.

But as stated above, the intake is an LS6 intake with AIR/EGR removed. Although my KR has happened since I bought the formula nearly 6 months ago when it was completely bone stock down to the stock lid.

Also to note the KR only happens when it wants to, not all the time. As before when I had my old MAF it happened at every WOT run but now just from time to time with the screened MAF I replaced it with.

Tootall

iTrader: (78)

anyone else? . . . I'd like to nail this down tomorrow. I'm really interested in tuning with the drivers side O2 sensor out, and have my WB there in place instead.

E V I L

iTrader: (6)

TTT.

So my options are:
1)Address PCV problems -98's are common to have faulty PCV?
2)Replace knock sensors and harness with newer units? -98 Problem, although I am hearing actual knock as well as some false knock.

Any other ideas? Thanks

Luna

iTrader: (6)

Replace the knock sensors and harness.

I'm not sure about PCV. I've never heard that 98s in particular had any more problems than any other years with oil consumption through the PCV system.

I scrapped my entire PCV system capped it all off and installed a breather. Car runs much better since then

Rhino

iTrader: (6)

Can your wideband also emulate a narrowband o2? What are you using?

Tootall

iTrader: (78)

sure can, I just read up on that.

I have a LM-1 WB

disable closed loop - set it to 284
disable LTFT
disable MAF = 0


thanks for the suggestions, anything else ?

E V I L

iTrader: (6)

I wanted to bring this up as to see if anyone else had any opinions. We will be replacing my knock sensors and harness this weekend and are hoping that this fixes the problems but since he is doing the tune, maybe someone has some other insight. He is going to set my VE tables back to stock and attempt to tune my MAF. Thanks

Luna

iTrader: (6)

From what I understand, if your VE isn't right modifying MAF is just a band-aid fix.

mvvette97

iTrader: (18)

I am tuning a 98 camaro right now and have the exact same problem. 4 degrees in the 3500 rpm range.

BLK02WS6

iTrader: (2)

You can put it in open loop and pull one of the front factory O2 sensors for the wideband - that's the way I do it all the time. In open loop, the factory O2 sensors aren't doing anything anyway. After you completely tune the VE tables and then the MAF table in open loop with the wideband, put it back in closed loop, reinstall the factory O2, and check the LTFTs. If the LTFTs are way off, or one is higher than the other, you need to check for leaks, or you may have a worn out O2 sensor.

And yes, the 98s are bad about KR. You can tune on the knock sensor tables to desensitize them, but it is hard to know how much to do on them so you don't totally disable them... I usually make small changes and see when the false knock goes away. If the tune is on, and it is knocking, chances are really good it is false knock.

Luna

iTrader: (6)

Just replace them with the updated style sensor and harness and the false KR goes away. There are different part numbers. Just do a search and you will find them

Tootall

iTrader: (78)

thanks for the suggestions, I'll take a crack at it again this weekend.