OBD-II trouble code
P2282: Air Leak Between Throttle Body and Intake Valves
Air is reaching the manifold itself without passing the throttle plate. This is the only one of the three intake-leak codes that describes a true vacuum leak, and it drags in every accessory the manifold feeds.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $25 – $1,100
- DIY difficulty
- Intermediate DIY
Browse every code in P2200–P229F, or start from the full code library.
What does P2282 mean?
Past the throttle plate, the intake manifold is the one part of the engine that spends its life at strong negative pressure — around two thirds of an atmosphere below ambient at closed-throttle idle. P2282 says air is crossing into that volume somewhere between the throttle body and the back of the intake valves, without passing the throttle plate that is supposed to be metering it.
That pressure difference changes the character of the fault completely compared with a leak further upstream. Air is pulled through the opening hard enough to make noise, so this is the code where listening actually works, and it is the code where a length of hose held to the ear will walk you to the hole. It also means the leak has authority: the module can close its idle-air control all the way down and the engine still idles high, because the leak is feeding air the idle control has no way to take back. An idle that sits several hundred rpm above specification and refuses to come down no matter what the module commands is a signature this span produces and the other two do not.
The search is wider than the manifold casting, because the manifold's vacuum is distributed around the engine bay. The brake booster, the crankcase ventilation valve, the evaporative purge valve, exhaust gas recirculation, and on older vehicles a tree of climate-control actuators are all connected to this volume. A torn booster diaphragm, a purge solenoid stuck part-open or a perished actuator hose is an intake leak even though the manifold itself is perfect. A hard brake pedal alongside this code is a strong hint and costs nothing to check.
On a port-injected engine there is one more boundary inside this one that is easy to forget. The injectors sit in the manifold or head with rubber seals at their lower ends, inside the leak boundary this code describes. A hardened injector seal admits air at a single port, which leans one cylinder while the others stay correct — so a single-cylinder misfire alongside this code moves the search to the injector seats rather than the gasket faces. Composite manifolds add their own failure: modern plastic plenums are welded assemblies with integral runner flaps, and a hairline crack along a weld seam or around a runner control shaft can be effectively invisible and may only open once the plastic is hot.
Common causes
- Intake manifold gasket leaking at the cylinder head face
- Throttle body mounting gasket failed or bolts loose after cleaning
- Torn brake booster diaphragm or a failed booster check valve
- Hardened injector lower seals admitting air at one port
- Evaporative purge solenoid stuck partly open or its line split
- Crankcase ventilation valve jammed open on the manifold side
- Cracked weld seam or runner control shaft seal on a composite intake manifold
- Exhaust gas recirculation valve not seating, or its gasket leaking
- Perished or disconnected vacuum hoses to accessories fed from the manifold
Symptoms
- Idle sitting high and refusing to drop to its normal speed
- Audible hiss or whistle from the engine bay that rises and falls with engine speed
- Rough or unstable idle that smooths out as the throttle opens
- Lean codes or a single-cylinder misfire code appearing alongside it
- Hard brake pedal, or brake assist that feels weaker than usual
- Cold-start roughness that improves once everything is up to temperature
- Hesitation on light throttle with normal power under load
Diagnostic steps
- 1.Listen first. With the engine idling and the fan off, work around the manifold with a length of hose held to one ear; this is the one intake section where the leak makes a sound you can follow.
- 2.Check whether the idle is high and whether the module has already commanded its idle-air control closed. A closed command with an elevated idle proves air is arriving that the module cannot regulate.
- 3.Press the brake pedal several times with the engine off, then start it. A pedal that does not sink, or a booster that hisses continuously, points at the booster or its check valve rather than the manifold.
- 4.Clamp the purge line to the manifold and see whether the idle steadies. A leaking purge solenoid is a common and inexpensive find.
- 5.Read fuel trims per bank on a V engine. A one-sided skew localises the leak to one head's gasket face; an even skew points at the throttle body, the plenum or a shared accessory line.
- 6.Look for a single-cylinder misfire in the misfire counters. One cylinder leaning out on its own moves the search to that injector's lower seal.
- 7.Inspect the gasket faces for the dark, clean streaks that mark a leak path, especially on an engine that has had the manifold off before.
- 8.Smoke-test with the throttle body sealed and watch the plenum welds and the runner control shaft bosses on a composite manifold, since those leaks are invisible dry.
- 9.If the leak only shows hot, repeat the smoke test at operating temperature. Plastic manifold cracks frequently close up cold and open as the assembly expands.
Repair cost
$25 – $1,100
A split vacuum hose or a purge line is $25 or less. A throttle body gasket is typically $60 to $180 fitted. A brake booster check valve is $30 to $120; the booster itself is $250 to $700. Intake manifold gaskets are the expensive end at roughly $200 to $900 depending on layout, since a V engine needs the plenum and often the fuel rail off. A cracked composite manifold that has to be replaced outright can reach $1,100 including labour. Injector seal kits run $150 to $450 fitted.
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DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.