While holding at 2,000 rpm to warm up the engine, I noticed a pulse in engine feel/sound like every second it was revving faster and slower slightly even though the rpm gauge held steady. No engine codes and runs fine, in park. Currently, I'm not 'allowed' to take it for a drive until May, so I don't know if it also happens when driving. The only thing I can guess it could be is some sort of harmonic created by the exhaust because one of my tail pipes is shorter than the other? Looks like it was installed too level/tipped up and it held water and rotted out. The sound/feel of it is very sine wave, very smooth up and down. I don't know that it's necessarily a problem, but it's not something I'm used to.

 

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