🔥 Trending Diagnostic Codes
Which check engine codes are people searching for most right now? Updated May 18, 2026.
📈 Rising DTC Searches
P0456 small evap leak
+108%Interest: 88/100
check engine light
+83%Interest: 27/100
P0420 catalyst efficiency
+45%Interest: 40/100
P0401 EGR flow
+32%Interest: 60/100
P0442 evap leak
+26%Interest: 20/100
📊 Always-Searched Codes
P0430 catalyst bank 2
Score: 68 +10%
OBD2 scanner
Score: 35 +9%
P0341 camshaft position
Score: 54 +3%
P0455 large evap leak
Score: 15 -1%
P0300 misfire
Score: 44 -4%
🗺️ States with Most Check Engine Searches
| # | State | Score | |
|---|---|---|---|
| #1 | Texas | 96 | |
| #2 | California | 93 | |
| #3 | Florida | 89 | |
| #4 | Ohio | 92 | |
| #5 | Pennsylvania | 84 | |
| #6 | Michigan | 81 | |
| #7 | Georgia | 76 | |
| #8 | Illinois | 76 | |
| #9 | North Carolina | 81 | |
| #10 | New York | 74 | |
| #11 | Virginia | 68 | |
| #12 | Tennessee | 71 | |
| #13 | Indiana | 71 | |
| #14 | Missouri | 66 | |
| #15 | Arizona | 65 | |
🚀 Breakout Code Searches
DTC-related queries exploding in search volume.
1 P0300 misfire Honda Breakout 🔥
2 P0442 evap leak Honda Breakout 🔥
3 P0442 evap leak Ford Breakout 🔥
4 OBD2 scanner Toyota Breakout 🔥
5 how serious is check engine light +3000%
6 P0442 evap leak fix cost +3000%
7 OBD2 scanner fix cost +3000%
8 can I drive with P0171 system too lean +1500%
9 P0442 evap leak causes +1500%
10 P0171 system too lean after oil change +900%
11 check engine light won't clear +500%
12 P0171 system too lean Honda +500%
13 P0128 thermostat symptoms +500%
14 how serious is P0128 thermostat +500%
15 P0128 thermostat DIY fix +500%
About DTC Trends Data
This page tracks which OBD-II diagnostic trouble codes Americans are searching for most. Trending codes often indicate widespread vehicle issues, seasonal patterns, or recently discovered problems affecting specific makes and models.
Why Check Engine Codes Trend
- Weather changes: Cold weather triggers P0128 (thermostat) and O2 sensor codes. Summer heat causes cooling-related DTCs.
- Fuel quality: E85 and seasonal fuel blends trigger P0171/P0174 lean codes in waves.
- Model-year defects: As vehicles age, batch defects emerge — causing specific DTCs to spike.
- Recall announcements: NHTSA recalls drive massive search spikes for related codes.
Methodology
We monitor 15+ DTC and check engine light keywords weekly using Google Trends data for the US market. "Rising" means 15%+ growth over the prior period.