2 exhaust issues
 

First, where do you guys get you o2 sensore. i was just quoted 210 from mazda and there are only 6 left in the usa? Will the bosch from autozone work well? Will it hold up to the egt?

Second, is there some kind of trick to keeping the flanges tight. I now from the header flang to the tailpipe have fresh grade 8 hardware, new stainless exhaust piexes and coper gaskets. I am forced to tighten everything every 2 days cause it keeps loosenong and its getting annoying.

Please excuse my typos, my android phone isnt as rasy to type on as my old tp2.

The Bosch will work just fine. Try using some lock nuts & see if that helps on the exhaust.

The stock ECU runs pretty fat, I doubt that the EGT will hurt any sensor. I think all narrow band O2 sensors are the same anyway (with the exception of heating techniques).

The 'secret' to the exhaust flange tightening is to beat the car around for a while, pull it into the garage and immediately tighten the extremely hot bolts to a very snug level.

You should check your engine mounts, a bad engine mount will cause exhaust pipe loosening.

I doubt that your stock engine torques hard enough into good mounts to do much flexing of the exhaust.

I think my trans mounts and engine mounts are pretty warn. What I have been doing is every few nights, really run the car the last 2 minutes of my commute and then toss it on the ramps and tighten the hell out of the extremely hot hardware. I do think you may be on to something with the motor/trans mounts, mine seem loose. I guess thats the next upgrade.

Go polly!!! :)

Copper rtv on the nuts and bolts along with locking washers. That should pretty much eliminate any type of loosening your experienceing.

Zack.

That's a real stupid thing to do.
Copper RTV is only good for like 700F intermittent - see package.
It turns to dust on a rotary exhaust, unless you're talking about fasteners back in the rear muffler.

Also, no locking washer on the market can handle high heat.
Locking exhaust nuts are the only solution.


-Ted

Nothing wrong with the Bosch O2 sensors.

That's what I thought he meant. I know on the header it'd be useless but on anybof the flanges after the header I don't quite think they get that hot. Shoot I know of someone that's been building aviation and road race rotaries since before I was born that uses mearly tub and tile silicone for header gaskets and doesn't have a single issue with it. The heat may be there but on a n/a it's such a low pressure area that a leak isn't that likely. Iirc and exhaust leak will actually pull in outside area through the scavenging effect.

The bosch sensors work fine. I know that was already stated but just incase you still doubted it there you go.

You can get them with the stock connector on them at Autozone for just a few more dollars then one without one. Buy the one with the connector. I am currently trying to get ahold of the factory sensor connectors at this time and they will be available seperately as soon as I get them. All will be converted to S5 spec connectors as they are really just a better piece anyways.