Flashing P0300 SES on Highway PLEASE HELP!!!!!
#1
Flashing P0300 SES on Highway PLEASE HELP!!!!!
I have an 03 blazer xtreme that i had to change engines in and i bought an engine out of an 05 1500 pickup with a 4.3L. After everything was changed and running im now getting a random misfire on deceleration around 75mph and flashes for about a minute and stops and will start again shortly after until i get off the highway and slow down. Now driving around town its fine, ive basically replaced everything but i started doing alil research and the knock sensor off the engine i got is different then the one off my original engine. I put my old sensor on the new engine but im wondering if i should put the sensor that fits the new engine on mine because i think its sending the PCM incorrect readings and tripping the computer. Please any help is much appreciated, ive been fighting this issue for months now.
#2
The PCM is programmed to the vin of the vehicle. That may be some of your problem. Also, when I received a tuned pcm, I had to have a crankcase relearn done to it as well. The tuner reprogrammed the pcm to match my vin but you have to have the right scan tool to do the crankcase relearn.
#7
I dont know how to check it. I have a matco scan tool that i can read some of my parameters and i saw one called "ign advance". I noticed when the light starts flashing the ign adv starts retarding and advancing like crazy and then when its running normal it always stays in a certain range.
#10
Edit: there are a lot of variables to consider the advance at idle. Anywhere from 15 to 30 is not uncommon.
https://blazerforum.com/forum/tech-articles-diy-29/edi-engine-timing-24373/
This link should help you out on it. But yes ignition off should be 0, I will have to check what is the acceptable range for idol.
https://blazerforum.com/forum/tech-articles-diy-29/edi-engine-timing-24373/
This link should help you out on it. But yes ignition off should be 0, I will have to check what is the acceptable range for idol.
Last edited by 50lb_cat; 06-26-2012 at 02:29 PM.