P0135: O2 Sensor Heater Circuit Bank 1 Sensor 1
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - main cost is fuel economy during warm-up and an emissions test failure.
Symptoms
- Check engine light
- Slightly worse economy, especially on short trips
Likely causes, most common first
- Burned-out O2 sensor heater element (age-typical)
- Blown fuse feeding the heater circuit
- Connector or wiring damage
Read P0135 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0135 concerns the heater inside the bank 1 upstream oxygen sensor. The heater exists to bring the sensor to operating temperature quickly; without it the sensor still works once the exhaust heats it, which is why the engine feels normal.
Check the fuse before buying a sensor - heater circuits share fuses with other components on many cars, and a fuse is the two-dollar version of this repair. Otherwise, sensor replacement is routine and permanently settles it.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P0135
“My 2004 honda civic has approximately 38,000 miles on it. One day while driving home the check engine light comes on and tells me the oxygen sensor bank 1 sensor 1 heater sensor circuit is bad. The error code is p0135. Make a long story short numerous people have ran into this problem which occurs right outside of warranty. Brought it into honda dealer and got charged $602.34 for a twenty minute job. I couldn't pass inspection with the check engine light on so I was forced to do it. I did not notice and decrease in fuel economy at all. *tr”2004 Honda Civic · Sep 2008 · 38,000 mi
“Tl*the contact owns a 2002 chinook destiny 2400 (na). The contact stated that the vehicle would not start after several attempts. He hooked up his obdii scanner, which read that there was a crank position sensor failure (p0135). The contact purchased and installed the part. There is an investigation (ea06016) regarding this failure. The current and failure mileage were 24,640.”NHTSA complaint · Oct 2007 · 24,640 mi
Cars that report P0135 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P0135?
Yes - main cost is fuel economy during warm-up and an emissions test failure.
How much does it cost to fix P0135?
Typical US repair costs range from $40 for the simplest fix (fuse or wiring repair) to $450 in the worst case. The right number depends on which cause your car has - see the causes list.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.