Half of the engine not firing

SOURCE: more 99 cougar problems

there is a fuse for the o2 heaters if one of the sensors blew the fuse they will all be out

SOURCE: 2003 tahoe

For p0300 ,p0240 on chevy tahoe 00- 06 check a wire going along with the battery ground to the engine block thre should be a high resistence on the small wire ,it gets corrode over time ,it should be located on underneath of the driver side engine,

SOURCE: I got 96 chevy c2500 pickup, 5.7 vortec, engine

Check your bank 2 plugs for colour (do they look hot like they running hot ). Check you EGR Exhaust Gas Recirculation valve (looks like a 80mm diameter spaceship with a vacuum line to the top of it) If this remains closed the engine runs very hot and causes misfire. Possible causes are EGR not opening are 1) perforated diaphragm 2) encrusted valve stem 3) clogged exhaust gas feed pipe. A quick check for function: run the engine and remove the vacuum tube. The engine note should change as the tube is connected and then disconnected. Also pushing on the underside of the EGR with your fingers to lift the diaphragm to open the valve should also result in change in engine note. If its not working just disassemble the EGR and clean with carb cleaning spray, also clean the exhaust gas feed pipe likewise.

SOURCE: i have a 2003 chevy

The coils are the next place to look.

SOURCE: I have a Mercedes s500

Hi!!
What all this codes have in common is that every single one of them can be caused by a vacuum leak, so carefully check for cracked, loose or disconnected vacuum hoses, wiring to the coils, fuel pressure regulator, fuel injectors, specially on cylinder 2.

• PO100 - Possible causes are wiring harness failure, air leak or defective hot film MAF sensor
• PO130 - Vacuum leak
• PO170 - PO173 - Possible causes are air ingress (leak), fuel injector failure, pressure regulator failure or mechanical wear of engine. Inspect and repair as necessary.
• PO300 - possible causes are vacuum leak, wiring harness failure or ignition coil defective.
• PO302 - If limit value for misfire "harmful to TWC" is exceeded, the MIL flashes immediately. If too many combustion misfires occur in one cylinder, the cylinder is switched off (cylinder selective fuel shut off). After the affected cylinders are shut off, the MIL changes from flashing to continuously lit until next time the engine is started. If combustion misfires are recognized, the fault code P0460 or P0462 is set if fuel tank level is too low (fuel reserve indicator light is on). Combustion misfires due to a shortage of fuel are recognized by means of this additional information.

NOTE:After cylinder cut-out system is turned off, the system monitors (through misfire detection) if all intake and exhaust valves are open again.
NOTE:Misfiring may be caused by many faults in the fuel injection system. Usually a misfiring fault is stored with faults pertaining to other components. An engine mechanical fault could also cause a misfire condition.
Good Luck!! A HELPFUL - 4 THUMBS - rating for this solution would be greatly appreciated. Thank you for using FixYa.