After my Lude was tuned I was told to expect my air/fuel ratio to read around the High 13's / low 14's while at idle and cruising, b/c h22's run better on the rich side.

now, two months later, with the temperature dropping in PA, I'm noticing that my ratios are wandering into the upper 14's and occasionally into the 16's for a second. Is this normal to see with the cooler/denser air?? Or do I need a retune, or to fix something??
thanx for any help

 

when it gets cold and more dense, your a/f may rise.

 

But is that a bad thing...or just normal.

 

I'm guessing you are tuned on Uberdata or Crome. Don't worry about A/F's when you are just driving around with no load. As long as you are not missing (lean missfire) you'll be fine. Make sure when in boost or have a big load on the car without boost the AF's are in the 12.2 or lower

 

nah it is hondata and as long as the a/s's are still good under boost youll be ok.

 

to do a quick fix w/o a retune, just bump up the fuel pressure a bit (try increasing it by 5psi)

 

IAT correction tables are found at 0x5516(low load); 0x5531(medium load); 0x554c(high load).

It follows a temperature, Correction(word, not byte), temperature, correction, temperature, correction....pattern.

Anyone with a little motivation, logic, and computer knowledge should be able to handle hex editing the ROM. Another big hint is to use whats available to you(download sManager, Crome, and Uberdata....should give you big hints, especially since uberdata and crome's scripts are able to be opened in word pad)

 

Yes it's a hondata s200 on a P72. Thanks for all your input.

a few more Q's -
How do you increase the fuel pressure? All this tuning stuff is foreign to me....
and also - doesn't the new s300 system compensate for atmospheric changes??