I installed a set of ebay dna longtube longtubes with the dummy cats and have been having a few issues. Before the install my wideband would read 14.6 or 14.7 in park. After install in park it was 16 - 16.3. I've looked through every thread i could find and have yet to see anyone with the same problem. I have HP Tuners but im new to tuning and still trying to learn. I did get it back in the neighbohood of 14.7 but only after going SD, disabling my maf, stft and ltft and tweaking my v.e. table. I did see one post where it was said that if the 1st o2 sensor was too close to the collector, it could get false readings. Anyone know if there is any truth to that? Any help pointing me in right direction would be appreciated.

Thanks, Ronnie

 

I had problems with my o2s not heating correctly. Also, any exhaust leaks can cause a lean reading. There is also the possibilty that it just needs a retune.

 

ull need a retune, and turn ur rear o2's off...

 

This^^. You are moving a lot more air through the engine with the less restrictive exhaust. That is why it is so lean. You need to read the help files on HPT forum and maybe go through the ls1tuningguide.com tutorial. You have to adjust fueling in the VE and also the MAF table.

 

thanks for the input guys. I think Kelsey hit it on the head. I found an exhaust leak, fixed that, now the readings are looking much better.

Thanks again.

 

Glad to hear that you've got it cleared up.