P0174 on a Nissan
Quick answer
On Nissan VQ-series V6 engines, P0174 isolated from P0171 is documented to more often trace to a bank 2-specific intake gasket leak, while a MAF sensor contamination cause, being sensor-wide, typically produces both lean codes together.
Severity 2 of 4. Short trips only.
Fix soon · Short trips only
| Code | P0174 |
|---|---|
| Standard name | System Too Lean (Bank 2) |
| Make | Nissan |
| Severity | Fix soon (2 of 4) |
| Safe to drive | Short trips only |
| Tool needed | Scanner with live data |
TOPDON TopScan Lite OBD2 Scanner, Bidirectional Scan Tool, 8 Resets & AI
Adds live sensor streams and freeze frame, which is what turns a code into a diagnosis rather than a guess.
Coverage varies by tool and by model year, so check a specific tool against a specific vehicle before buying.
What is different about P0174 on a Nissan?
Since Nissan's dominant lean-code cause, MAF contamination, affects the whole intake stream, an isolated P0174 is a useful signal to look at bank-specific causes instead.
Patterns documented on Nissan vehicles
Bank 2 intake gasket wear on VQ-series engines: The same documented intake manifold gasket wear pattern on Nissan VQ-series V6 engines that can cause P0171 applies to the bank 2 side as well, and an isolated P0174 points more toward this bank-specific cause.
MAF contamination as a whole-system cause, not isolated: Because Nissan's documented MAF sensor sensitivity to aftermarket filter contamination affects total measured airflow rather than one bank, it is a less likely sole explanation when only P0174 is present without P0171.
What to check first on a Nissan
The order below narrows the generic P0174 list down to what is worth checking first on this make. It is a starting order, not a diagnosis: patterns are generation specific and a vehicle outside those generations may have none of them.
Check in this order
- Check whether P0171 is also present; an isolated P0174 points toward the bank 2 side specifically
- Inspect the intake manifold gasket on the bank 2 side of VQ-series V6 engines
- Inspect bank 2 vacuum connections
- Only investigate the MAF sensor if both lean codes are present together
The generic picture behind P0174
This mirrors P0171 but for bank 2 of a V configured engine. Long term fuel trim on that bank has been pushed well beyond normal correction range trying to add fuel, indicating unmetered air or insufficient fuel delivery specific to that bank, or a shared intake issue affecting both banks.
Everything on the main P0174 page still applies here. This page narrows the cause list to the patterns documented on Nissan vehicles, it does not replace the underlying definition.
The generic version of this code
Tools that can diagnose P0174
Adds live sensor streams and freeze frame, which is what turns a code into a diagnosis rather than a guess.
- LJPXHHU
OBD2 Bluetooth Scanner Car Code Reader for iOS, Android and Windows
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$13.98 Check pricePrices change often - Veepeak
Veepeak Mini Bluetooth OBD2 Scanner Code Reader for Android (NOT for iOS)
- wireless
$14.99 Check pricePrices change often - MOCATEC
WiFi ELM327 OBD2 Adapter WiFi ELM 327 OBD Scanner for Universal 12V Vehicle
- wireless
$15.95 Check pricePrices change often - UMEIJA
OBD2 Scanner Diagnostic Tool, Car Scanner for iOS & Android, Bluetooth 5.4
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$29.99 Check pricePrices change often
Common questions
Why would only P0174 show up and not P0171 on my Nissan V6?
An isolated P0174 on a Nissan VQ-series V6 typically points toward a leak or gasket issue specific to the bank 2 side of the intake, since a whole-system cause like MAF sensor contamination usually affects both banks and would be expected to trigger both codes.
Is the MAF sensor still worth checking if I only have P0174?
It is less likely to be the sole cause of an isolated bank 2 code, but it does not hurt to inspect it, especially if an aftermarket oiled air filter is in use, since Nissan MAF sensors are documented as sensitive to that type of contamination.