e36 fuel issues? please help! out of ideas!

[ereid74]

Hi i could not find a thread that was already posted that has answered my questions so here i am. I bought a 1999 bmw 323is with 155 miles on it for 5 grand ...first week the clutch went out ...second week the return off of the radiator nipple broke off...and after i fixed all of that about 2 weeks ago i realized it would bog down at about 5500 rpms and would not rev past...not thinking much of it i just shifted gears and still went past a local dodge neon with fruity flames/dragon decals a huge spoiler and the worlds biggest fart pipe....but a couple days after that i realized it bogged down and would not go past 5 grand...couple days after that it was 3500 which then became a major problem..i free revved it with the clutch engaged and it went up to about 5500 then stalled..now its to the point were it will only idle and it will just bog down upon hitting the gas...i hooked it up to my neighbors laptop and we were getting decent readings from the MAS but the o2 sensor was sluggish...loops werent jagged just roller coaster like..but still working..i cleaned the injector which were not clogged to begin with...the fuel injector plug ins were all working just fine after plugging in a test diode into each injector plug in and cranking over the engine...i dont believe this to be limp mode?? the cpu is only throwing one code which is ...p0420 catalyst efficiency below threshold...not sure what that exactly means..but im running 89 octane and am halfway through a full tank....the catalytic converter has some loose crap in it but the exquast flow seemed to be ok and increased with the rpms...im just lost and dont wanna sell it but ive gone through alot in a month and its starting to hit my wallet!...no performance parts on it..plugs look to be alright and are bmw ngks new airfilter and oil ....any help will be appreciated thanks!!..ps im only 18 and am just getting into the bimmer world! keep me a fan!

[choffa]

Fuel pressure low, clogged filter or worn pump. Pressure tap on the fuel rail for testing it under load.
Throttle position sensor (should have thrown a code)
Broken catalytic convertor, excessive back pressure. They should not make any rattling noise, a dead giveaway that the ceramic matrix is broken up.
Damaged muffler baffles, again excessive back pressure

[bmwdirtracer]

+1, convertor is kaput, pipe's clogged with crumbled ceramic

[ereid74]

[quote=choffa;14204941]Fuel pressure low, clogged filter or worn pump. Pressure tap on the fuel rail for testing it under load.




Already tested pressure underload and fuel pressure did not drop! im most likely going to hack off my old catalytic converter and weld on a new one

[ereid74]

deos anybody else have any idea?? or is this def it?? thanks

[ereid74]

converter was shot! about inch by inch pieces of ceramic were everywhere in the exhaust..because i do not have the money for a new converter i just cut open the old one and removed the ceramic and welded it back up.

[bmwdirtracer]

Love those check engine lights.

Go to Bimmerworld for a kit to defeat the CEL (O2 sensor fooling device); it's for racing E36's, but it will do the job, if you care.