hey guys hopefully someone can help me. i bought a 04 rx8 with a bad engine. i bought a reman engine, new coils, new plugs, and new leads from mazda. i installed them the car started perfectly. i have a p0410 DTC, the pump works for about 2 minutes when the car is dead cold. the car feels gutless over 4k rpm even though it revs all the way to 7k rpm. my Cataylic over heated its self slightly melted and the 1st bank shattered so i smashed out the rest since that cat can no longer be useded for emission testing. car runs the same. the car gets about 13mpg with a combination city to highway driving although i would say about 70% highway. i suspect fuel problem but dont know exactly where to start leaky injectors? low/high fuel pressure? fuel regulator? fuel pump? thermo choke/ cold start? not sure but the car uses a ton of fuel and has little power with new engine and no cat i should have more than enough.m please help me diagnose i am running out of money quickly commuting in this car since my bike blew a piston.

 

Did you install the engine or did mazda? If mazda installed the reman then it will have a 1 year 12k mile warranty, if not then I don't believe there is a warranty. When your cat failed was that after you put the reman on or was it a little melted before? The p0410 should not affect the drivability of the car though.

 

I installed the engine myself. i kept getting misfire DTC's so i took the car to the dealer and told them the story and asked for their full diagnostic reading of the car the only thing they said was that they had to calibrate the eccentric shaft position sensor since i had swapped engines and that they had did it for me without extra charge, and that was it. i didn't really take a good look at the cat when i swapped engine but im pretty sure it had to be slighly damaged from all the water and steam going through it from the first engine that had bad coolant seals. but it definitly was not broken. earlier i did suspect a clogged cat so i bought some expensive cataclean cleaner and ran it once, although i don't think that is the reason my cat broke but the cleaner may have hurt it. i do have a warranty on the engine it is one year 12k miles. BTW its the 4-speed automatic edition which i hate.

 

UPDATE After many hours of troubleshooting I have found the main problem with my engine. On the driver side of the engine on the underside of the extension intake manifold there is a.small vacuum line about one inch long long with a one way check on it. Mine was unplugged on one end. Now I have about 50% more power over 3500 rpm. I have not driven the car far yet to compare fuel mileage but I expect omg mileage to increase.

 

make sure you do the 20 brake pedal stomp and clean the eccentric shaft sensor. Could help your fuel economy. Because 13mpg is terrible. You should be getting above 20 with a new engine. Did you check if there are any pending codes that could affect your mpg? For instance intake solenoid, SSV ?