Depending on where you get smogged at, you may get hassled if ANYTHING in your engine bay doesn't look stock. Doesn't matter if it's legal or not, most "techs" at the smog check places wouldn't know their left hand from their right. I had one guy hassle me for my PAINTED VALVE COVERS, and completely missed the adjustable FPR (which is illegal). In the end, he tested me and passed me. I have since found a smog place that DOES know their stuff and I don't have problems now.
Heh, that's a story in itself. I went to get smogged at the current place, and the guy asked me about the Goodyear blue hoses I had. I presumed he thought they weren't legal, so I started arguing with him. He replied "I know they're legal, I want to get a set for my Toyota. Do you know if they (Goodyear) makes em?"
Sadly (for him) they don't, but that impressed me enough. Even better, they got a guy working there now that owns a 95 Cobra.
I've invited him here, but he doesn't get online much.