I have a 2002 chevy blazer it's throwing a p0507 code I have replaced IAC, TPS, and PCV, along with all my vacuum lines I can't find any vacuum leaks and I need to smog soon I really need help with this any info will help

 

Do you have any performance symptoms at all? For instance does it seem to be idling higher than normal (>650 rpm) after initial start up? Do you have access to a code reader that can read the freeze frame data for when the code was thrown (or even better yet live data)? If yes to viewing the freeze frame data, what was the RPM when the code was thrown? What was the IAC counts? Normal is 650 rpm and IAC counts of 18 (if we're talking a 4.3L). If you have access to a scanner that can show live data...same questions at idle. If the idle rpm is higher than 650 and the IAC count is around 0, it indicates a vacuum leak. If that's a case take a bottle of water and dribble it around the vacuum hose connections and around intake mounting surface to see if you can hear the water get sucked in.

 

Check your throttle body for being gummed up. idle air controller. Throttle positioning sensor. Vacuum leaks. Inspect all your hoses.

Get some throttle body cleaner or Carb cleaner and spray around the intake looking for a change in idle. Coolant temp sensor

Mine ended up being a bad spider injector.

 

2nd to ROCKP2's advice. What are the IAC counts at idle? if it is controlling it should be between zero and 60.

Teach a man to fish.........

https://blazerforum.com/forum/diagno...plained-35140/