Enter the error code and car brand

Vehicle engine and/or automatic transmission

Code: P219B - The air-fuel mixture on engine bank 2 is not within the normal range, affecting engine performance.

P219B is one of those codes that, when it shows up, tells me right away there’s an air-fuel imbalance happening on Bank 2 of your engine. That’s the group of cylinders on one side-usually the side without cylinder one, but check your service manual to be sure. What this code is really saying? At least one cylinder on that bank isn’t getting the same air-fuel mix as the rest, meaning it could be running rich (too much fuel) or lean (not enough). The engine control module keeps a close eye on these ratios because the engine runs best, and lasts longest, when every cylinder is working in harmony. I’ve seen this across all sorts of brands-Cadillac, Chevy, Ford, GMC, and Nissan. They all use P219B as a signal that something’s off with the air-fuel balance, even if Nissan might phrase it a bit differently. Bottom line: if you see this code, your engine’s not burning fuel the way it should, and you’ll want to get to the bottom of it before it starts causing real trouble.

Causes of P219B code

From my time under the hood, I can tell you that P219B almost always tracks back to something affecting how air or fuel gets into those cylinders. Here’s what I run into most in the shop and what official service info backs up:

Leaking or dirty fuel injectors-these things can throw off your air-fuel ratio in no time flat.
Low fuel pressure-or simply running the tank way down-can cause uneven fueling.
Leaky EVAP purge valves-these let unwanted vapors or air sneak into the intake.
Intake or exhaust leaks-unmetered air (or escaping exhaust) really messes with the mix.
EGR (exhaust gas recirculation) issues-this can disrupt combustion if it’s not flowing right.
PCV (positive crankcase ventilation) leaks or stuck valves-lets in extra air you don’t want.
Ignition faults-bad spark plugs or coils are classic culprits behind imbalance codes.
Believe it or not, something as simple as a loose oil cap, dipstick, or fill plug can pull in extra air and confuse the system.
On Nissans, I’ve seen faulty mass airflow sensors, poor cylinder compression, or even wiring faults at the injectors or coils be to blame.

If I had to bet, I’d put my money on a fuel injector or air leak, but you can’t afford to overlook any of these possibilities. Always work through the whole list.

Symptoms of obd code P219B

Usually, the first thing you’ll spot is that dreaded check engine light. Sometimes, the engine will run rough-especially at idle, when you’re sitting at a light or just started up for the day. I’ve had plenty of customers complain about lousy fuel economy, and sure enough, this code pops up when you’re making more trips to the pump than usual. You might also notice hesitation or a flat spot when you hit the gas. If the problem gets worse, you could get misfires or the engine stumbling under load. But sometimes, I see cars with nothing but the warning light-no other symptoms at all. Don’t let that fool you; it’s still worth tracking down.

Diagnosis process for obd2 code P219B

This is my go-to process for chasing down a P219B code:

Start by scanning for other trouble codes. Sometimes, another code gives you a direct clue-don’t skip this step.
Next, I get hands-on with a visual check. I hunt for cracked or loose vacuum lines, make sure the oil cap and dipstick are buttoned up tight, and look over all wiring and connectors for any sign of damage or corrosion. I always check for intake and exhaust leaks-those can be sneaky.
On to the fuel system. I’ll check fuel pressure with a gauge and look at injector condition for leaks or clogs. If I have a scan tool handy, I check fuel trims or do an injector balance test.
Then I move to the ignition side of things. I pull the spark plugs and check how they look-fouled plugs tell you a lot. Coils get tested if there’s any doubt.
Nissan owners: don’t forget to check the mass airflow sensor and make sure every PCV hose is snug and leak-free.
If everything looks good up to this point, I’ll run a smoke test on the intake and EVAP system. Tiny leaks can hide anywhere, so this step’s critical.
If all else fails, I check for mechanical problems like low compression in a cylinder. Sometimes, the guts of the engine are to blame.

Here’s a pro-tip from the garage: always start with the easy stuff-a loose cap or a split hose is way cheaper to fix than a set of injectors. Double-check the basics before you dive into deeper diagnostics.

Common Mistakes when dealing with P219B

A classic mistake I see: folks rush to swap out pricey parts like fuel injectors or sensors before checking for the simple stuff like air leaks or a loose oil cap. Another one? Overlooking wiring and connectors-corrosion or a bent pin is easy to miss but can cause all sorts of headaches. Skipping the fuel pressure check is another pitfall; low pressure is a sneaky cause of this code. I’ve also seen people ignore other codes stored in the computer, not realizing the real issue is hiding behind something else. Don’t get caught guessing-work step by step, and you’ll save yourself a lot of time and money.

Seriousness of P219B engine code

Let me be straight with you-this isn’t a code you want to let slide. If you keep driving with P219B, you’re risking damage to the catalytic converter, fouling up your spark plugs, or even causing misfires that turn a small problem into a big one. I’ve seen engines go from a simple air-fuel issue to needing major repairs just because someone put it off. If the engine starts running too lean or too rich, you’re flirting with real trouble. Don’t wait-get it checked out before something expensive breaks, or worse, leaves you stranded.

Repair tips for dtc P219B

Once you’ve tracked down the real cause, here’s what usually gets P219B off your back:

Give those fuel injectors a good cleaning or replace them if they’re leaking or clogged.
Seal up any vacuum, intake, or exhaust leaks you find-replace anything that’s cracked or broken.
Swap out a bad EVAP purge valve, EGR valve, or PCV valve if they’re the culprit.
Install new spark plugs or coils if they’re worn or faulty.
Make sure the oil cap, dipstick, and filler plug are tight and sealing right-replace them if needed.
Nissan folks: sometimes it’s a flaky mass airflow sensor or even bad wiring at the injectors or coils. Don’t overlook those.
If fuel pressure’s low, a new filter or pump might be the answer.

Here’s my standard advice: after any repair, clear the code and take the car for a decent test drive. Make sure it doesn’t come back before you call the job done.

Conclusion

Here’s the bottom line: a P219B code means your engine’s air-fuel mix is out of whack on one side, and ignoring it is asking for trouble. This isn’t something to put on the back burner-track it down and fix it before it snowballs into bigger, costlier repairs. The best approach? Start with the basics: look for air leaks, fuel delivery issues, and ignition faults. Work through each possibility, and in most cases, you’ll nail down the problem without too much hassle. Act fast, and you’ll keep your engine running strong for the long haul.

Video for "Error p219b" on YouTube