P0440 indicates and evaporative system failure. Unless you are mechanically inclined take it to a good mechanic or Chevy dealer. If you are inclined get the repair manual for the unit and follow the diagnostics there-in. BTW don't waste your hard eraned $$$ on Chiltons... Haynes or Factory is worth the $$$
Usually a problem in the emission control system-have vehicle scanned to determine the problem
When service engine light is on on a 2003 Chevy Trailblazer, the problem could be a faulty thermostat, a circuit range performance problem, or any other problem.
Fuel pump is my guess.
You must first find out what caused it to come on and that will REQUIRE an engine scanner. After you have scanned the engine and read the engine codes and then repaired the problem. You will be able to turn the light off with the scanner.
It is on because the ECU has detected a problem with the emissions system.
Valves will clatter if the engine is overheating.Valves will clatter if the engine is overheating.
the service engine light is on due to the fact that there is a problem with your truck, this is confirmed by the way your truck is running. you need to get a engine diagnostic check at an auto shop. may just need a tune-up, or the truck has a bad sensor, or engine woes.
You will have to get a engine scanner and scan the engine. And it will give you the trouble code or codes, and then fix the problem. The computor is seeing a problem in the engine system or transmission system. Need to repair.
Have vehicle scanned to determine problem and have codes cleared
You need an OBD II scanner.....about $40 - $150 depending on where and which features you want.
You must have an engine scanner to do that.
Do it yourself engine transmission flush and filter change on 2005 Chevy silverado 5.3?"