I have a proton waja 1.8,after replace ecu,can not start up the engine

I'm assuming when you say "converter" your referring to the catalytic converter (Cat)? Sadly in modern vehicles doing a "Straight Swop" on a transmission isn't that simple. Your vehicle's engine and transmission electronics are set up for an Automatic transmission. It will have some sensors that a manual doesn't have and not have other sensors a manual does need.
Did you have the vehicle's ECU, (brain), reprogrammed to work with a manual transmission. If you didn't the ECU will be getting confused signals which can put it into some sort of 'Safe' setting.
Removing (Deleting) the Cat can also cause issues.
The Muffler and the Audio kit shouldn't affect the engine unless there's been a mistake wiring in behind the head unit.

It certainly could be, but I wouldn't jump to that conclusion so quickly. Leave such diagnosis' to the pros, who often zero in on the most expensive component without proper troubleshooting.

Typically, troubleshooting would start with seeing if you can get a spark at the spark plug. Then work back from that (assuming the starter is turning the engine over properly). This means spark plug, leads, disributor cap, distributor rotor, electrical continuity to the distributor and coil. About the last thing on the list is the (expensive) ECU.

Get it scanned. A proper scanner would show what is wrong. A few probable causes, namely speed sensors, AT position switch, wire harness and eventually TCM.

Replace relay that is UNDER the engine bay Fuse Box. It has no fan switch. Fan relay controlled by ECU.

hi,
the engine speed sensor should replace
your engine won't start if the sensor can't read the 0 timing angle point on flywheel.

Check alt bat

check all fuses does the check engine light come on some cigar lighter fuses power the ecu

test the ignition coil see the instruction attached AND fix it.
God bless you

saya sedang mencari sesiapa yg nak menukar enjin auto kereta waja ke enjin manual..
Sesiapa berminat sila hubungi saya di 010-9090 767

if it is like my 4 banger '99 MB, remove the "panel" from on top of your engine