Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

2014 corvette hpt

General Tuning Discussion

Forum Posts



Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads


Evening all,

I have a c7 vette z51 package. Just finished installing Texas speed long tubes, full exhaust, new plugs, and wires . This particular exhaust does not use reat o2s on the primaries. Using hp tuners I disabled the DOD and tuned off all the error codes for the downstream o2s and AFM. No other adjustments have been made to the fueling tables as yet. My issue is the car is now showing LTFT of 26-30% on bank 2. Bank 1 is around 5-10%. I also have random misfires on cylinders 2, 4. 6, and 8. I smoked tested the intake and oil sump and found no leaks. Has anyone had issues as this? Thanks in advance.

Hello Mark

Smoke test the exhaust for leaks before going much further, if you have limited tools get the injectors checked or swap them left to right. also check the basics like spark plugs in case they have been damaged during the installation of the pipes. think basics and keep it simple for a start.

Regards Ross

Thanks for the reply Ross. The plugs and wires were replaced after the headers were installed. Another bit of info. The misfires will randomly disappear as well as the fuel trims going back to normal. I had to use quite a bit of heat on the o2 sensors together them loose. Do the o2s have that much influence over the operating parameters?

I would replace the O2 sensor on bank 2. But you could test this first by swapping the O2 sensors between banks, and see if the misfires and rich trims follows the sensor currently in bank 2. A failing sensor tends to run lean, and that would cause the trims to add fuel, which could then lead to rich mis-fires (which looks very lean...)

Good Luck.

Great point David I will swap sensors and see what happens. Smoked tested everything I removed for the install and didnt see anything so I am leaning towards the sensor being no good.

Changed the rear o2 sensor on both as I did put a lot of heat to them but no change. Is there anything that can cause this type of issue in the evap system?