P1167 on 1996-1999 Honda Civic (DX, LX, EX, Si, HX) — Air/Fuel Ratio Sensor 1 Heater System Malfunction
1 vehicles · 1 makes · $250-$700 repair
How to diagnose and fix P1167: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Honda Civic · 1996–1999
The stock cast-iron exhaust manifold on sixth-generation (96-00) Civics is prone to heat-cycle cracking, typically right next to the front oxygen sensor. On SOHC D16Y7/Y8 cars the catalytic converter is integrated into the manifold, so the crack lets outside air reach the O2 sensor, skewing fuel trim and triggering rich/lean plus catalyst-efficiency codes, along with a ticking/exhaust-leak noise.
Common Symptoms
- Ticking or exhaust leak noise, worse when cold
- Check-engine light with fuel-trim/O2 codes
- Rich running, poor fuel economy
- Fouled spark plugs
- Rotten-egg smell / cat damage over time
How to Fix
Replace the manifold. Options include an OEM manifold, a two-piece Dorman replacement, a Walker manifold/cat combo, or an aftermarket header. Welding is generally not recommended as repairs rarely hold on the thin cracked casting.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Dorman 674-439/673-439 D16Y7-style integrated exhaust manifold and catalytic converterOEMDorman 674-439 federal / 673-439 CARB branch
D16Y7 integrated-manifold/converter replacement after the casting is confirmed cracked Fitment/availability: Dorman direct OE crosses are Honda 18160-P2E variants used on selected 1996-2000 Civic DX/CX/LX D16Y7 applications. Enter exact …
Sources for this issue (3)
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P1167 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P1167 mean?
P1167 stands for "Air/Fuel Ratio Sensor 1 Heater System Malfunction." A manufacturer-specific code used by Honda and Acura for a fault in the heater circuit of the upstream wideband air/fuel ratio sensor (bank 1, sensor 1). That sensor has to reach operating temperature quickly for the PCM to control the fuel mixture accurately; when the PCM commands the heater on and the circuit's current or resistance stays out of range, it sets this code. Expect the check engine light, possibly slightly reduced fuel economy, and an emissions test failure. Other manufacturers reuse P1167 for unrelated concerns, so confirm the make before diagnosing.
What are the most common causes of P1167?
The most common causes of P1167 are: Failed air/fuel ratio sensor heater element (sensor replacement), Blown air/fuel sensor heater fuse, Damaged, melted or chafed sensor wiring near the exhaust, Corroded or loose sensor connector, Open or shorted heater power feed / ground circuit, Poor engine ground causing excessive voltage drop, Faulty PCM heater driver circuit (rare). The specific cause varies by vehicle.
How much does it cost to fix P1167?
Repair costs for P1167 range from $250 to $700, depending on the vehicle and root cause.
Which vehicles are affected by P1167?
Au7o has documented P1167 across 1 vehicle models from 1 manufacturers: Honda.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.