Q: Car Codes p300 through p306 go off and code p1406

asked by on April 05, 2017

Car Codes p300 through p306 go off and code p1406. Also car does shake at certain speeds; one day it will shake when I am going around 20-30mph and other times it will start shaking at around 60-70mph. If the car is on, but parked it emits a heavy burned gas smell. I have taken it to a few different mechanics and none of them were able to fix the direct issue. They have been able to alleviate some issues though to be honest with you. So far what has been done, changed the oxygen sensor twice, rebuilt the transmission, replaced ignition coils, I have changed the gas cap, and still it has the blinking engine light on. Last mechanic said it could be EGR valve, but the bolt is stripped and I cannot get it out with my home tools. I do not want to sound overly exaggerated, but please tell me you can help out without having to pay an arm and a leg again to attempt to fix it.

My car has 228000 miles.
My car has an automatic transmission.

Exhaust Gas Recirculation/EGR Valve Replacement $160.41 - $965.47 Get a Quote

Hi There, Code P1406 relates to the EGR valve as you may know. The EGR valve is a small component designed to allow the flow of exhaust gases into the intake manifold in controlled amounts. Whenever you start the engine, the valve comes activates and waits in a closed position, blocking the flow of exhaust gases. Once the engine reaches operating temperature and speed increases, the valve, either through vacuum or electronic control will gradually open, allowing burned exhaust gases to enter and combine with the air-fuel mixture inside the combustion chamber. When the EGR valve is clogged or dirty, as they are prone to, it may not function properly causing the engine to idle rough, stall at idle speeds, cause the car to get poor fuel mileage, or emit a strong smell of fuel due to excess hydrocarbons which also results in failing emissions tests. I would suggest having a professional from YourMechanic come to your location to take a look at your vehicle to properly diagnose and repair.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Meter fuse keeps blowing out
Hello there, a few different things can cause the fuse to blow like this. It is good that you have identified the fuse that is blown, as this will makes it easier to diagnose. Fuses do not blow for no...
My Nissan b15 drive good on flat road but not uphill, it goes uphill in reverse only. Why it can't go uphill in drive gear.
I'm not sure if you are saying the transmission is slipping when in drive, or that the engine isn't making enough power. One way of checking this is by checking for severe exhaust restriction. That will allow the engine to...
The temperature gauge goes above middle too hot
If the gauge is moving into "hot" territory, then the car is overheating. You will not necessarily leak water during an overheat. Overheating can be the result of a couple of different failures. I will start with the easiest to...
Truck bogs down at wot.
Hi there. It appears as if you've checked all the usual suspects that can impact acceleration "bogging" issues except for two the throttle body and fuel injectors. When you're quickly applying throttle to a fuel injected engine, having a clean...
The engine makes a noise when it is in neutral or when i drive.
Hi there. The noise you are hearing could be the torque converter (automatic) or clutch (manual). The part could be loose or have a balance issue causing the part to move around and make some sort of noise. If the...
Need my 2004 Freestar camsfaft synchronizer replaced, cost?? 2004 Ford Freestar
Hi there - from your description, it is hard to tell whether you need the [camshaft position sensor](https://www.yourmechanic.com/article/how-long-does-a-camshaft-position-sensor-last, or the camshaft position actuator (sometimes called the variable valve timing actuator or solenoid (https://www.yourmechanic.com/services/variable-valve-timing-vvt-solenoid-replacement)). Please forward the problem codes (Pxxxx) for...
Is the throttle body on a 2010 Chrysler Sebring apart of the transmission or are they 2 different things?
Hi There, The throttle body is entirely separate from the transmission and does not have anything to do with the transmission. It sounds like the vehicle may have gone into a reduced power mode. It may be possible that the...
I have a 2012 Audi Q7 that consumes a quart of oil every 500 miles
This can happen for a couple of different reasons such as worn piston rings or leaking valve guide seals. Blue smoke coming from your exhaust (https://www.yourmechanic.com/services/smoke-from-engine-or-exhaust-inspection) generally means that the motor is burning the engine oil. When this happens, the...
Engine vibrates then becomes full shake as if wanting to turn off but no check engine light on side note 2016 Nissan Altima 44,000
Hi Elsa. Thanks for contacting us today. There are a few reasons why a car will vibrate like you are describing. Typically, the most common source is that the engine or motor mounts are worn out. This tends to happen...

Related articles

2012 Toyota Corolla vs. 2012 Honda Civic: Which One Should I Buy?
Compact cars are the unsung heroes, slightly larger than a subcompact, but not quite big enough to be classified as a mid-size sedan. These vehicles have a small wheelbase of no longer than 109 inches with between 100 and 109...
The Best Used Cars to Buy If You're On a Budget
If If you’re on a budget and need to purchase a car it can feel as though it’s slim pickings. Thankfully, there are plenty of great options available even to those on a tight budget. Let’s take a look. The...
Should I Buy a Honda Accord or a Toyota Camry?
The Honda Accord and Toyota Camry have been the best-selling cars for 20 years due to their quality and reliability. Find out which is best for you.