Hondata

My 08 cr with Vortech SC has been getting worse mpg over the last 6 months, i went from 24 mpg down to 19 mpg. My driving habits havent changed and I am still driving to and from the same place since ive had the SC installed. I changed the spark plugs from OEM to copper about 6 months ago as well. So i dont know if that would cause a problem.

I just had the S2k dyno'd and the results were that its running a full point leaner, from 11.58 to 12.61. Boost is down as well, it peaked at 5 psi, where previously it peaked at 8 psi.

Any ideas on what could be wrong? Also, what heat range number spark plug should I be using? OEM heat range plugs are 7, the copper plugs heat range number is 5.

Thanks.

Are you using a Hondata system?

Yes, have the Vortech system -> 4HS218-060L that comes with the ECU reflash from Hondata.

My car is a 2008 S2000 CR.

The 2 issues are most likely unrelated. You need to look at your long and short term fuel trims to see what might be going on, as you may just have O2 sensor that is on it's way out. The boost level changing is purely mechanical.

It looks like the ECU is throwing the P0113 code for the IAT sensor, but the CEL isnt coming on. Does that make any sense? Could the IAT sensor be causing my problems.

I have heard that Honda put out bulletin regarding code P0113, if the IAT sensor is good, then the ECU needs to be reflashed. Have you heard of this?

What do you mean that it is throwing a code, but there is no check engine light? How are you determining this?

The guys running it on the dyno had the ECU hooked up to their PC. The CEL wasn't coming on, but their PC was picking up the code P0113. I'm guessing the IAT sensor is on its way out, would this cause it to run lean??? Are their aftermarket IAT sensors that I should get since I have a Vortech SC kit? What are your recommendations?