The problem that I am facing is with the very high NOx value and replacing the air flow sensor for my 1986 Volvo 240 DL.

Note: {}=15mph test, []=25mph test

About 2 years ago, I had the 02 sensor, tac door actuator, and cat converter replaced. The HC and CO readings decreased from {105ppm}, [100ppm] to {48ppm}, [33ppm] and {0.34%}, [0.33%] to {0.01%},[0.01%] respectively. However, NO values did not improve that much (before repairs {3288ppm}, [3116ppm]: after repairs {3209ppm}, [2928ppm]. I opted for the 2 year extention since that was my allowed budget at that time. The total cost for parts and labor were $993.47: I paid $493.47 and the CAP deducted $500. Until today, the car did not have any major problems. I now have to decide if I should replace the air flow sensor ($495) so that the car can operate or donate/recycle the car since even if I replace the air flow sensor, I still need to fix the NO problem by Aug 2006, which is when my 2 year extention ends. Any advice would be greatly appreciated. Please let me know if I should post more information about my car or smog test results. Thank you.

 

you can buy a used air flow sensor very resonably about $25. go to www.car-part.com search for your specific part then go to the page with an asterisk for the lowest price. I bought two good ones for $20 each! This is why I work on my own car.

 

Dear wojeepster,

Thank you for the quick reply. From the provided link, I selected 1986 and Volvo 240 but could not find air flow sensor or mass air flow sensor in the "Select parts" section. Is air flow meter the same term for air flow sensor? I'm sorry for asking all these questions.

Edit: Would replacing the bad air flow sensor improve my chances of passing the smog test? I should mention that I live in California, Foster City.

 

yes that is correct. Get the number off the side of your mass air flow 212 xxx xxx 007 from my distorted memory (look at yours don't go by my memory). Then when you call make sure you get the same number. Yes it will improve your chances as the car will run very poorly with a bad one. In the eary years of fuel injection cars had air flow meters so that is what it is call on that website. Good luck to you.

If I remember correctly high nox is from high combustion temperatures