Could the MSP16 PCM reflash explain the blue smoke on startup?
 

I’ve noticed that my new to me 2004 Mazda rx8 occasionally smokes a good bit on start up. Smoke starts roughly 15-30 seconds after start up and starts slowly going away until it’s completely gone 3-5 minutes after start up. Smoke increases with revs as well. there is also a smell like it has no cats on it even with the stock exhaust set up on it which also goes away largely after 3-5 mins. Could it be from the reflash, cats heating up, or failed cats? Also could be the oil seal but engine is healthy besides the smoke.

Sounds like condensation. And yes these cars smell on a cold start. Oil needs pressure to enter the chamber so most of the time oil leaks show up under high rpm/load, not start up.

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MSP16 wouldn't cause anything like that. Even if you ran the OMP wide open, it would not produce enough oil to be noticeable.

It definitely appears to be a bluish smoke though. My running theory is that it’s just premix and the cat isn’t warm enough to pull it out of the exhaust fumes. Haven’t owned it long enough to know if oil the consumption rate is average. Doesn’t seem to impact performance at all so I guess I’ll just live with it for now.

It would have to be a massive amount of premix. Keep in mind how little fuel (and so premix) is injected at idle. If it smoked at idle, it would look like rolling coal at speed.

My bet is cold enrichment + condensation. But either way, no cause for concern as long as there are no other symptoms.

Maybe check if there's oil in your intake.

Aaaand that was it! Probably from when I topped it off with no funnel one time. Dang and I thought I could get away with not using a funnel just this time… lol

Well so there are two ways it gets in: one is awkward pouring, the othere is high rpm blowby. I would keep an eye on whether the oil returns without you topping up the oil. If it does you may want to do a compression test and set up a catch can to keep it out of the intake.

yeah I’ll likely get a catch can for it now so I don’t screw up a MAF. I’m thinking for now though that this was from awkward pouring because I pulled out the MAF and it had no oil on it and the oil in the intake only was in the ribs of the intake and didn’t go any further down. It all looked like fresh oil too which would make sense with the awkward pouring.

for now I’ll keep an eye on it to see if it goes away or progresses

I love the smell of Premix in the morning.

https://cimg3.ibsrv.net/gimg/www.rx8...dbe4061c8.jpeg