Hello!

I just picked up an FD about a month ago and have been learning and reading about it for a bit. I am really excited about it.

One thing I have rad is that the engine will run lean with too many mods and an aftermarket ECU should be used.

My car is currently all stock with a downpipe (not sure what brand), all stock piping ect...

Would it be safe to put a cat back on it without worrying about it running lean?

Thanks!
Lucas

 

Yes, keep the boost in check and you should be fine (10-8-10). I ran intake, dp, rb exhaust with a stock cat for years with a stock ecu. Use to be a 3 mod rule, but its now commonly thought the boost is what needs to be controlled

 

awesome! thanks for the info!

 

....and assuming you have a boost gauge to read that, you also need an aftermarket temp gauge. Stock FDs run hot and the stock gauge sucks

 

^ That is true and that is why mazda made the temp gague not linear because otherwise people would be freaking out. The problem with that is once the temp needle moves past the center, the car is NOT a little warm it is actually quite hot. So if the needle gets to the h you're done.

IMO though, an aftermarket temp gauge is not a necessity for a street car. Just make sure the stocker is always at center point and if it ever passes the center its time to take action. Of all the years that I've owned my fd (16 yrs) I've only once I've seen that needle move past middle... It was a 100+ degree day and I was driving through the desert with the ac on when all of the sudden my gauge moved to the 2/3 mark... I took evasive action immediately.

 

Maybe not. I was running 250+ when i blew my O-rings and don't think the stock gauge budged. Of course i was tracking it at the time

 

Since you say your gauge never moved im inclided to say that it sounds like your stock gague malfunctioned.