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07 EX 1.8L multiple engine issues / mechanic can't figure it out

1708 Views 4 Replies 2 Participants Last post by  07civicEXcoupe1.8L
Car is 2007 Civic Ex Coupe 1.8L engine 182,000 miles
I'll try to keep this short.
Here are the codes, I go into detail below.

P0172: Bank 1 Too Rich/Fuel Trim
P0300: Random/multiple cylinder misfire detected
P0301-P0304: All four cylinders misfire detected
P0108: Manifold Air Pressure (MAP) Barometric Pressure Sensor Circuit High Voltage Input Problem
P2649: "A" Rocker Arm Actuator Control Circuit High --- I have no idea why this came on or what it is
Possibly a P0400 (EGR not flowing)

This is what I did before the codes came on:
Replaced the EGR valve (and gasket)
Replaced fuel injectors (I made sure to oil all o-rings and do the idle re-learn by disconnecting the battery)
Replaced valve cover gasket (torqued to 7 ft-lbs in the correct order)
New oil and filter
MAP sensor is clean
Throttle body is clean
Battery and alternator are good
Air filter is clean
Compression test - all four cylinders had exactly 180 psi.
No fluid leaks at all
Replaced passenger side engine mount (doing the rest soon)
Replaced spark plugs (torqued correctly)
Replaced ignition coils
All fuses are good
My cousin replaced the fuel pump a while ago but it did not solve anything.

After doing ALL of this, the car still runs bad and puts out these codes. It stalls uphill way too easily (automatic trans btw), clunks when I press the gas again from coasting, and an 18 second 0-60 time. Insanely slow. I can't tell if it's in limp mode or not. I have to hold both pedals with both feet at stop lights. Trans fluid is full (measured with engine running) and looks relatively new. Starts fine in the morning but can take up to 6 seconds to start when already at operating temperature. This started happening immediately after I changed the fuel injectors and still happens a month later. I made sure to oil all o-rings and do the idle re-learn by disconnecting the battery, so it shouldn't take long to start but it does anyway.
If I hold it at any speed for a certain time the whole car will shake for three seconds and then stop shaking, for example when I'm just holding it at 32 or 50 mph, it will shake after a few seconds then stop. I assume this is what triggers P0300 through P0304, because it doesn't have a constant misfire.
When accelerating from a stop, the engine takes up to 3 seconds to grab before it starts accelerating, so I have to ease into the gas. It stutters and shakes and misfires for a good two seconds before finally going. At times it stalls. Catalytic Converter is 400 degrees at operating temperature. My mechanic says it should be 300 F normally. In park it will not rev directly to 5k, it stutters twice and then reaches 5k.

I'm hoping somebody has some guidance or previous experience with this issue that can help. Everything seems like it should be fine on the outside yet it still does this.
I need it to work properly and be reliable.

My next thought is to do a valve adjustment since I'm running out of options.
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Did you use Honda fuel injectors? The reason I ask is that I once troubleshooted a problem by replacing one injector at a time, each injector in turn, with a non-Honda injector, and it was clear that the injector was not compatible with my car. At one point, it even went into limp mode and the Check Engine Light was flashing. As soon as I got back to all Honda injectors, the problem went away.

Also, the P2649... is that indicating an unexpected voltage at the VTEC solenoid? Just wondering out loud. If so, it's interesting that voltages are out of bounds both there and at the MAP sensor. I'm just speculating though. You could try checking the wiring to those two areas.
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