Do ignition and engine sensors problems track on-road nitrogen oxide emissions, tons per year per 1,000 residents across states?
Across U.S. states, NHTSA owner complaints about ignition and engine sensors problems run higher where on-road nitrogen oxide emissions, tons per year per 1,000 residents is higher, after adjusting for the makes sold in each state. This is an association across states, not proof that on-road nitrogen oxide emissions, tons per year per 1,000 residents causes this repair. Too few complaints name this repair alone, so the on-road nitrogen oxide emissions, tons per year per 1,000 residents pattern is measured across all 19,176 complaints about the ignition and engine sensors, which this repair belongs to.
State reports of ignition and engine sensors problems against on-road nitrogen oxide emissions, tons per year per 1,000 residents, one dot per stateEach dot is a state: how much more (or less) than expected this repair is reported there, adjusted for the makes sold in the state, against its on-road nitrogen oxide emissions, tons per year per 1,000 residents (EPA NEI 2020)
How to read it: Each dot is a state. Further right means more on-road nitrogen oxide emissions, tons per year per 1,000 residents (epa nei 2020); higher up means more complaints for this repair than expected (1.0 is average). If the dots climb to the right, reports of this repair rise with on-road nitrogen oxide emissions, tons per year per 1,000 residents (epa nei 2020).
What it shows: States with more on-road nitrogen oxide emissions, tons per year per 1,000 residents (epa nei 2020) tend to sit higher on the chart across 50 states: a pattern in the data, not proof of cause.
Data: EPA 2020 National Emissions Inventory, on-road, joined to NHTSA owner complaints, downloaded 2026-10-06 · 50 states. Chart: CalcScrape · calcscrape.com
The 10 states with the most on-road nitrogen oxide emissions, tons per year per 1,000 residents (Wyoming, Montana, New Mexico, North Dakota, Idaho, South Dakota, Nebraska, Oklahoma, Oregon, Kansas): reports of ignition and engine sensors problems run 2% above what the makes sold there would predict, and 6 of 10 are above expected. The 10 with the least (District of Columbia, New York, Massachusetts, New Jersey, Vermont, California, Hawaii, Rhode Island, Maryland, Michigan): 3% below, and 3 of 10 are above expected.
Exceptions: Montana, New Mexico and Idaho are among the highest in on-road nitrogen oxide emissions, tons per year per 1,000 residents but report below expected.
Split the states into thirds: the third with the least on-road nitrogen oxide emissions, tons per year per 1,000 residents runs 4% below what the makes sold there would predict, the middle third 4% above, and the third with the most 6% above. Most of the on-road nitrogen oxide emissions, tons per year per 1,000 residents effect sits between the lowest and the middle third.
For on-road nitrogen oxide emissions, tons per year per 1,000 residents, after allowing for the 1562 comparisons we ran, luck alone would produce a pattern this strong about 1 time in 8. The on-road nitrogen oxide emissions, tons per year per 1,000 residents pattern leans on District of Columbia: without it, it weakens.
Weak spot: compare only states with similar cost of living index and the pattern keeps about 24% of its strength, so part of it may come from cost of living index instead of on-road nitrogen oxide emissions, tons per year per 1,000 residents.
For on-road nitrogen oxide emissions, tons per year per 1,000 residents, of the 5 exception states, 4 read the same way for the other parts of the ignition and engine sensors (so that is the system there, not this repair) and 1 are specific to this repair.
Where the on-road fleet puts out more nitrogen oxide per resident, emission-control parts are working harder and the places are more likely to enforce emission rules.