how come for some reason i cant get anything to log onto my laptop.....but when i use it on my desktop computer it picks up weird data....ex. 325 rpm when key is on start and engine not running...also 290 degree f for coolant temp....some weird stuff...and when i try to invert the rx,tx lines...they pick up nothing.....ohh and whats also strange is my CEL keeps on staying on..eventhough ive tried reseting it bout 5 times and it didnt happend before. not untill ive put on the rs233 to ttl. can somebody help me...

 

something wrong when u did some soldering.. check those. make sure they don't jump to other traces.