Where do you plug in the coder - 1993 Honda Civic 4 Door

contact gmc dealer and ask for pcm plug schematics, locate the power wire/s and check for juice, theres a short somewhere

code p 0340 refers to cam shaft (CMP)sensor A bank 1---circuit malfunction===causes --wiring---CMP sensor ---ECM
indications are faulty harness connections , faulty wiring (stopping the starting indications ) and lastly replace the sensor

Make sure your air filter and fuel filter are good. They can cause havoc. Have you checked for a vaccum leak? A leak can make your car act up like it has major problems. You still need good spark plug wires to get a good connection. I would check for the leak. A good way to check is by soapy water. Just watch it around electric parts and wires.

p0133 is for the oxygen sensor. It is a slow response. You most likely have a "heated" sensor and it isn't heating up fast enough. This is for the Bank 1, Sensor 1. That means that it is the one in the exhuast BEFORE the catalytic convertor on the back side of the engine ( cylinders 1-3-5)

most likely it is a wiring harness problem. maybe rubbing on the steering shaft at some point. May have worn through and broke at the wear spot. The security wiring for the key coder decoder circuit usually is in a harness going to the ignition switch. If it shorts or seperates it will not allow the engine to operate due too no signal to PCM (power control module). The coder/decoder reads the chip in the key and determines if the engine is allowed to be started.

The sputter you feel under load is either a spark plug wire or a torque convertor shutter due to transmission fluid not being serviced properly, A code scanner connot dictate these problems, You need it tested by a pro with a "Computer" that can read pids (Sensors) as it runs to eliminate un needed repairs..

you can get the radio recoded by an independent recoder, look in the yellow pages for radio de-coders they normally come out to you, costs about £20 to £40 some are cheaper.

normally when it says safe mode if you leave the power on the radio for 1 hour safe mode should disable if it is not doing this then it may be faulty.

Regards
Dan
p.s if you cannot locate a re-coder please send me your postcode or area and I will find you one near by.

check intake gasket for leaks...most common with high mileage..gm had a redesigned gasket that in green in color to repair this problem...hard to detect leak unless you really know what you are looking for..also check for proper fuel pressure and fuel filter

it sounds like the computer is the issue and thats why the code reader can't communicate with your expiditions computer