I have 1999 olds silhouette and there is a vacuum line that runs from the valve cover in the front of the motor to a t on the air intake. where does the line go to from there

Big breather from valve cover to air cleaner, the small vac line runs from there to the FPR.



These next are standing in front of the car:

Intake manifold lower outer runs to EZL

Intake manifold lower inner (right side) goes to switchover vac valve on driver fender. The other side of this vac valve goes to the throttle body

Intake manifold lower inner (left side) goes to switchover vac valves on passenger side fender. These then go back to the EGR valve once making a loop under the distributor cap for whatever reason.

Intake manifold rear runs to a 'three' way valve (or 'Y' connector) on the secondary firewall. This is usually a vac leak.

check your vacuum lines, first check the pcv valve line( usually runs from back of intake to top of front valve cover). at first glance it may appear to be in but they tend to slide out of the nipple slightly, push it back in and put piece of tape around to keep in place.

Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1.

Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.

Symptoms: You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.

Causes: A code P0171 may mean that one or more of the following has happened:
The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak downstream of the MAF sensor.

Possible solutions include:
In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace if necessary
Check for a dirty fuel filter and proper fuel pressure


This service should only take 3 to 4 hours, however they may have to order parts overnught, so that may be the reason why they recommend leaving it. Here is the article from Ford.

FORD: 1999-2003

This TSB supersedes articles 03-4-7 and 00-21-8.
ISSUE:
Some vehicles may exhibit a check engine light on and lean Diagnostic Trouble Codes (DTC's) P0171/P0174 (system too lean bank 1 or 2) stored in memory.
ACTION:

Do not replace PCM (Powertrain Control Module), MAF (Mass Air Flow), or HEGOs (Heated Oxygen Sensors), as these parts are not the root cause of the lean codes conditions described. Refer to following Service Procedure for details.
SERVICE PROCEDURE

These conditions may be caused by a loose fitting on the fuel pressure regulator vacuum line on the intake manifold end and/or leaking isolator bolts/port gaskets in the lower to upper intake manifold mounting area. This condition is sometimes intermittent and may not be apparent on a warmed-up engine.

If the vacuum line from the intake manifold to the fuel pressure regulator is loose at the manifold (due to oil contamination), replace the vacuum line (9E498) and install a new design LH service valve cover (6582). Another vacuum leak source is the gasket (9H486) between the upper and lower intake manifold assemblies caused by a loss of tension at the isolator bolt assemblies (9S479) due to contamination of the rubber grommets from excessive oil pullover.

Perform self test, if codes P0171, P0174 are the only codes stored in the PCM then continue with this article. For any other codes, follow the normal diagnostic procedures found in the PC/ED Manual.
(ALL 1999-2003). Reprogram the PCM (Powertrain Control Module) with the latest calibration, WDS B26.2 release or later. Do not replace the PCM. Reset the Keep alive memory.
(1999-2001 ONLY). Inspect the vacuum line from the intake manifold to the fuel pressure regulator for looseness, leaks and/or oil contamination and replace Vacuum Line (XF2Z-9E498-DD) if required.
(1999-2000 ONLY). Inspect the LH Valve Cover, it should be a (3F2Z-6582-BA) Install a new LH Valve Cover if required, refer to Workshop Manual Section 303-01 Valve Cover-LH. (Refer to the following NOTE for description of the old style valve cover).


NOTE: USING A SHOP LIGHT OR FLASHLIGHT, CHECK THE LH VALVE COVER TO SEE IF IT HAS ALREADY BEEN UPDATED TO THE LATEST LEVEL. REMOVE THE PCV VALVE AND RUBBER GROMMET FROM THE VALVE COVER AND LOOK THROUGH THE HOLE AT THE INTERNAL SHEET METAL BAFFLE. THE OLD STYLE VALVE COVER BAFFLE HAS A 3/16" DIAMETER HOLE IN THE 5:00 O'CLOCK POSITION AS YOU LOOK THROUGH THE PCV HOLE (FIGURE 1). VALVE COVERS FITTING THIS DESCRIPTION MUST BE REPLACED.


(ALL 1999-2003). Remove the upper intake and replace only port gaskets (9H486) and isolator bolt assemblies (9S479). The new isolator bolt assemblies use a rubber material that is green in color, do not use the old isolator bolt assemblies with the black rubber material (XF2Z-AA). Do not replace any other intake parts (black plastic or aluminum) or the lower intake gaskets, (9439 and 9A424/425) or the upper intake clamshell gasket (9461). Refer to Workshop Manual Section 303-01, Intake Manifold-Upper.
(ALL 1999-2003). While the upper intake manifold is removed, check the Exhaust Gas Recirculation (EGR) orifices that are pressed into each primary port of the lower intake manifold. If any of the orifices are plugged with soot, clean and unplug them with a pick and solvent.


CAUTION: DO NOT USE SMOKE DETECTION, PROPANE GAS, OR CARB CLEANER TO TEST FOR VACUUM LEAKS. (CARB OR BRAKE CLEANER MAY CAUSE INTAKE MANIFOLD RUNNER CONTROL (IMRC) BEARING FAILURE). SOME LEAKAGE FROM THE IDLE AIR CONTROL (IAC) OR EGR VALVE AND IMRC SEALS IS NORMAL. DO NOT REPLACE THESE PARTS, ESPECIALLY THE LOWER ALUMINUM INTAKE MANIFOLD.


NOTE: THIS CONDITION COULD ALSO BE DUE TO WARM AMBIENT TEMPERATURES AND THE USE OF WINTER GRADE FUELS WHICH HAVE VERY HIGH VOLATILITY AND MAY BOIL IN THE FUEL LINES (VAPOR LOCK) DURING A SHORT HOT SOAK. OXYGENATED FUELS WILL AGGRAVATE THIS CONDITION. IF NON-OXYGENATED FUEL IS NOT AVAILABLE, USE MID/HIGH OCTANE FUELS WHICH HAVE LOWER VOLATILITY AND MAY HELP ALLEVIATE THE CONDITION.


PCM CALIBRATION INFORMATION
Application Old Part Number (-12A650-) Old Tear Tag New Part Number (-12A650-) New Tear Tag Old Calibration New Calibration NGS/WDS Qualifier
1999-2000 49S LEV XF2F-ME ZHT2 YU7Z-EC N/A 9LMA-BEE 9LMA-BEE WDS B26.2 Release or Later
1999-2000 Calif. XF2F-HE NQE2 YU7Z-FC N/A 9LMA-BDE 9LMA-BDE WDS B26.2 Release or Later
1999-2000 Calif. ULEV CAT.RED YF2F-AB FGJ1 YU7Z-GC N/A 0A31AS0B05 0A31AS0B05 WDS B26.2 Release or Later
2001 50S ULEV 1F2F-BD UET3 1U7Z-DBB NYD1 1A31AS0507 1A31AS0512 WDS B26.2 Release or Later
2001 50S ULEV (CAT) 1F2A-AD TVM3 1U7Z-DTA TGA0 1A31NC507 1A31NC0510 WDS B26.2 Release or Later
2002 50S ULEV 2F2A-AC YUX2 2U7Z-AJA JPR0 2A31CA0506 2A31CA0506 WDS B26.2 Release or Later
2002 ULEV (CAT) 2F2A-DB OOZ1 2F2Z-DC OOZ2 2A31ZC0505 2A31ZC0510 WDS B26.2 Release or Later
2003 50S ULEV 3F2A-CB DLQ1 3F2Z-CB DLQ1 3A31BA0505 3A31BA0505 WDS B26.2 Release or Later

Obtain an Authorized Modifications Decal (FPS 8262 - obtainable through DOES II, 25/pkg) and list the date, dealer number, and summary of modifications performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.
AUTHORIZED MODIFICATIONS

THE FOLLOWING MODIFICATIONS HAVE BEEN MADE:
Reprogrammed Powertrain Control Module (PCM) Per TSB 03-16-1
THESE MODIFICATIONS HAVE BEEN APPROVED, AS APPROPRIATE, BY EPA AND CARB.
DEALER NUMBER:------------------------------------------DATE:

CHANGE AUTHORITY:

FPS 8262 9/78 FORD MOTOR COMPANY PRINTED IN U.S.A.





PART NUMBER PART NAME
XF2Z-9H486-AA Port Seal - Package of 6 (1 Pkg Req. Per Veh)
3F2Z-9S479-AA Isolator Bolt Assy. - Package of 8 (1 Pkg Req. Per Veh)
XF2Z-9E498-DD Vacuum Line
3F2Z-6582-BA Valve Cover - LH


Good luck.

The age of your vehicle guarantee's a vacuum leak. It may sound silly but the truth is rubber grommets and hose's shrink and dry out over time and the harsh environment under the hood makes it worse. Check all vacuum lines and fittings attached to the intake manifold, valve covers(pcv valve), and be sure to check for a vacuum fitting on top of the intake just behind the throttle body. Does it fit tight in the hole? You can seal loose fittings with a high-temp RTV (Red) silicone sealant/adhesive.

Have you hooked a scanner to the computer and checked the oxygen sensor(s)? If they are bad they could lean out the engine.

Also, a restricted exhaust system can lower engine performance. If you dont know old the plugs and wires are, replace them. With plug wires, its the age not the miles. How old is the coil pack? It could be "breaking down" at higher rpm's. Does your engine have a cam sensor? It would be located where a Distributer used to be on older engines.

Remember an engine needs three things to work properly...Air / Fuel / Ignition(Spark)

MAF sensor if bad, the engine may not even start let alone run.
MAP sensor on most Olds engines is located just behind the rear valve cover. It may have a 3 or 4 wire plug connected and a vacuum line. Its about 1 1/2 inches tall X 4 inches long X 3/4 inch thick.
Hope this helps and good luck!

2.6L Engine

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Drain the cooling system.
3. Relieve the fuel system pressure.
4. Remove or disconnect the following:
   • Negative battery cable
   • Hood
   • Accessory drive belts
   • Accelerator cable
   • Positive Crankcase Ventilation (PCV) valve and hose
   • Air intake duct
   • Fuel pressure regulator vacuum line
   • Canister hose
   • Brake booster vacuum line
   • Engine wiring harness connectors at right wheel housing
   • Ground cable connector at the intake manifold, starter and firewall
   • Heated Oxygen (HO2S) sensor connector
   • Alternator wiring connectors
   • Oil pressure switch connector
   • Starter motor harness connectors
   • Ignition coil connector
   • Spark plug wires
   • Distributor
   • Exhaust front pipe
   • Exhaust Gas Recirculation (EGR) gas temperature sensor connector
   • Air pump
   • EGR pipe
   • Heat shield
   • Exhaust manifold
   • Throttle Position (TP) switch connector
   • Cooling fan
   • Water pump pulley
   • Power steering pump
   • Intake manifold
   • Crankshaft pulley
   • Front cover
   • Timing belt. Refer to the Timing Belt unit repair section.
   • Valve cover
   • Rocker arms
   • Camshaft
   • Cylinder head

Cylinder head bolt loosening sequence - 2.6L engine

1. To install:
2. NOTE: Refer to Section 1 of this manual for the cylinder head torque sequence illustration. The illustration is located after the Torque Specification Chart.
3. NOTE: Lubricate the cylinder head bolts with clean engine oil for assembly.
4. Install the cylinder head with a new gasket. Tighten the bolts in sequence as follows:
5. Step 1: 58 ft. lbs. (75 Nm)
6. Step 2: 72 ft. lbs. (98 Nm)

1. Install or connect the following:
2. Camshaft

• Rocker arms
• Valve cover
• Timing belt
• Front cover
• Crankshaft pulley. Tighten the bolt to 87 ft. lbs. (128 Nm).
• Intake manifold
• Power steering pump
• Water pump pulley
• Cooling fan
• TP switch connector
• Exhaust manifold
• Heat shield
• EGR pipe
• Air pump
• EGR gas temperature sensor connector
• Exhaust front pipe
• Distributor
• Spark plug wires
• Ignition coil connector
• Starter motor harness connectors
• Oil pressure switch connector
• Alternator wiring connectors
• HO2S sensor connector
• Ground cable connector at the intake manifold, starter and firewall
• Engine wiring harness connectors at right wheel housing
• Brake booster vacuum line
• Canister hose
• Fuel pressure regulator vacuum line
• Air intake duct
• PCV valve and hose
• Accelerator cable
• Accessory drive belts
• Hood
• Negative battery cable

1. Fill the cooling system.
2. Start the engine and check for leaks.

The old style fits into the timing cover that has the small hole for the actual distributor shaft. The old style also has no vacuum lines connected to it, or no provisions for vacuum lines to be connected to it.

The newer style has one vacuum line that runs from the elbow that connects the throttle body to the MAF, and another vacuum line that goes to the drivers side of the intake manifold. The timing cover has a hole about 2 inches in diameter for the newer Opti, the old version has a hole about 3/8" in diameter. If the distributor is installed look for the vacuum lines on the opti. The one that goes from the intake elbow attaches to the drivers side front in about the 2, O clock position. The one that attaches to the intake manifold attaches to the drivers side too, at about the 5, O clock position.

The air/duct controls on this are vacuum operated and you most likely have either a leaky vacuum line or a bad vacuum check valve. When the engine is running at a steady cruising speed there will be quite a bit of vacuum in the intake manifold and thus in the vacuum lines and control system. This vacuum is held there by a check valve so when you are accellerating and the intake vacuum drops you won't lose this vacuum. If there is a leak or the check valve is bad then as the vacuum drops the air doors move to the default position which is where the air is directed to the defrost vents. The vacuum line under the hood is usually black plastic and about 1/8" diameter. The line and check valve are on the right side of the intake manifold area towards the rear. I'd start my search there as that's where you'll probably find your problem. Hope this helps!

vaccume leak check all small and medium lines for cracks if cracked then you must replace. or its the pcv valve that rattles. its on your front valve cover. good luck. [email protected]

check for disconnected vacuum lines,or worse thing is intake gasket slipped and leaking

get a code # from code scanner and let me know and will assist further if can. autozone will scan for free.