ehh I dont let my cat touch my car anymore... last time I let him swap out my valve springs and he got hairballs in the cylinder and his claws effed up my paint. If he messed up the tranny that would be the end of him...
jkI've been havin some minor shifting oddities lately with no codes, I'll chime in when I get my new downpipe and cat in the next month or so and see if it improved conditions.