I drive a honda accord 2000 SE with 186,400 miles on it. The transmission started showing some problems since the last few months and has been getting worse. The gear shifts with a jerk. When i stop the car, the comes to neutral with a jerk. When i start it starts with a jerk. Otherwise at higher speeds it is smooth.

I get the confirmed error codes as P1739, P1738,P0420, P1259. Details in the pictures. I bought a camry and want to sell this car. However the dealers are lowballing me sighting these problems. I am thinking whether it makes sense to go for a repair for these as without any of the problems i could easily net $ 1500-2000 more in private market vs trade in.

Appreciate your opinion

 

The descriptions you listed are kind of off, so I'll go by the codes and use the explanations in the Honda Shop Manual. You'll have to address one at a time.

P0420 will likely require a new catalytic converter. It may be worth a shot to replace the downstream/secondary O2 sensor as the O2 sensor is less expensive.

P1259 has to do with the vtec system. Is your engine the 2.3 Vtec?

P1486 is a cooling system malfunction. Does the gauge in the car read normal coolant temps, or is the car overheating?

P0740 is for the lockup solenoid on the transmission.

P1738/P1739 are for the 2nd and 3rd clutch pressure switches respectively.

I'd start with very simple and inexpensive tests/fixes first. The vtec system uses oil pressure, sol check your oil level for the P1259. Maybe change your oil and filter.

When the engine is cold, remove the radiator cap and make sure the radiator is filled to the top with coolant. This could fix the P1486 code. You can also try a cooling system pressure tester as a loaner tool from advance auto. See if the radiator/cooling system can hold ~15 psi.

The P0740, P1738, and P1739 are all transmission codes and the transmission runs off of hydraulic pressure of the automatic transmission fluid. I'd check the transmission fluid level. When was the last time you change the fluid? My next step is "controversial", but I'd drain and top off with 3 quarts of Honda ATF-Z1 or equivalent and drive around. Drain, drive, then refill two more times to exchange most of the fluid. If the dirty fluid is helping the clutch packs grip, then clean fluid could make them slip more. My opinion is that worn clutch packs means the transmission is not long for this world anyways.