Well i installed test pipes on my 07 HR and it was driving nice and fine untill a few hundred miles later CEL comes on bank 1 and bank 2 cat deficiency, which i knew was coming but thats not the issue. Ever since that happened engine power and vehicle speed begin to slow down at WOT and honestly just sounds terrible. i notice the rpms dip maybe 500 rpms at wot and hold for a sec then back to full power. I’m assuming maybe i need a tune bc Air fuel ratios are off ? Has anybody else experienced this issue?

Thanks,