AskPatty Certified Female Friendly Logo
I had a Smog test in California on my Dodge Dakota Truck 3.9L Engine. Because of high NOX, it was at 15 on the MPG test portion. The mechanic said it needs to have the injectors cleaned. What is your take on this? All other parameters of smog test passed.

Answers from the Automotive Experts

Helaine Kurot, Owner/Technician at 360 Automotive NOX is the result of higher than normal cyllinder temperature. Usually, this is related to an EGR system not functioning properly. If the car is running to lean from a clogged injector, this could cause an increase in NOX. If the cooling system is not functioning properly or the fan is not coming on, this will also increase NOX.

Amanda J. Pierce, MBA You have have carbon build up in your fuel system, that after cleaning, can raise MPGs.

Colleen McGee, Driving Instructor at Americas Driving School Hi Alana Your mechanic is probably right. clogged fuel injectors reduce the amount of fuel getting to the cylinders, thus causing too high air to fuel mixture which would cause high NOX. To help keep the fuel injectors clean, buy high quality gasoline (use a well known name brand like Chevron or Shell) they have detergents to keep your system clean that cheaper gasoline does not have. Happy Driving! Colleen M.

Contribute to this question:


blog comments powered by Disqus

Related Dodge Dakota FAQs


  • Is the 4 cylinder engine friendly or unfriendly? Read More
  • Had a code 340 crankcase positioning sensor installed on my 2002 Dodge Dakota, but it ... Read More
  • The hazards lights on my 2004 Dodge Dakota came on randomly last night and would not turn ... Read More
  • I have 2.5 liter motor I'm rebuilding for a 2000 Dodge Dakota, I would like to what holds ... Read More
  • Truck does not like to start when wet( dry it out at distributer and it starts), is not ... Read More
  • why does my dodge dakota whine as i drive down the road? i already changed the wheel ... Read More
  • Front brakes: when applied there is a jerky motion like they are catching and releasing. Read More
  • What should I check if my power locks in my 2001 Dodge Dakota keeps unlocking when I am ... Read More
  • I have no start problem on 2000 dodge dakota with 4.7 engine. what does engine diagnostic ... Read More

Need Car Advice?

Ask The Experts!

Find Cars For Sale

Help Our Charities