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Discussion Starter #1
Just bought 2006 Mazda 6 had to get exhaust, camshaft sensor, crankshaft sensor, VVTsolinoid, water pump, and timing chain replaced..... YES!!! I got ripped off on buying the car. Went to pick up car and was told everything was good to go including brand new o2 sensor put in. He added that the car was shaky and that it should stop. I left and noticed check engine light come on immediately and car was shaking which it wasn't before timing chain replacement. Brought it back and o2 sensor code popped up again.
** QUESTION ***
ANYONE KNOW WHY MY CAR WOULD SHAKE AFTER GETTING TIMING CHAIN REPLACED AND WHAT REASONS AN O2 SENSOR COULD BE TRIGGERED. Also should I drive my car with it shaking???? THANK YOU
 

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W/o actually seeing the symptoms... the direct answer is NO.


Which engine do you have? How many miles?
The 3.0L have a beefy timing chain and those should last a long time. Timing chains are much more durable than belts.

It is possible that the Timing is a little off. If that were the case then you would have loss of power and misfires. That may/will cause "shaking". If it is severely off, then you will have a whole other mess such as damaged pistons & valves.

Check the all mounts.
Check oil level and confirm it is of proper weight & viscosity and other fluids.

Do not drive the car if it is visibly shaking more than "normal". It means something is amiss. Solve that first.

Excessive shaking will inevitably cause more damaged down the road. ie; stress fractures/metal fatigue in the frame; transmission; mounts; wiring; all those system plumbing... driver's safety, et al.

All vehicles' engine will have some sort of engine vibration but not to the extent of actually "shaking" if it is tuned properly. Because of the engine and transmission mounts all, that vibration is mostly absorbed by it. Engine & transmission are engineered to be force balanced. Unless it is a high HP/Tq and heavily cammed engine.

As for the HO2S,.. Depends on the code and which sensor(s) were replaced. Is it calling for the same sensor to be check/replace? The engine will not run correctly if the upstream sensor is malfunctioning. For the 3.0L... the are FOUR (4) HO2S in the system. The Mazda 6 tends to be sensitive w/HO2S. Always go w/OEM

Which part of the exhaust was replaced? the entire system? Or just parts that were rotted/rusted out? Is the catalytic converter in good shape and not clogged? A clogged/restricted exhaust will also case the engine to "shake" due to lack of free flow.



ALSO, Because of all this work, I would reset the ECU again and let it relearn all the new parameters. Before doing that, would definitely get many freeze frames for references.
Note all DTC.
 

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** QUESTION ***
ANYONE KNOW WHY MY CAR WOULD SHAKE AFTER GETTING TIMING CHAIN REPLACED AND WHAT REASONS AN O2 SENSOR COULD BE TRIGGERED. Also should I drive my car with it shaking???? THANK YOU
I would say the timing is set incorrectly. Likely the cam and crank are not in phase.

Set TDC and take the rocker cover(s) of and check the cam positions.
 

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Thank you all for your input it helps me greatly.
Car Details: 2006 Mazda 6 V6 3.0L with 179,000 miles

Called mechanic and asked what was going on now with the O2 sensor and the shaking, and he said the codes for the O2 sensor popped on the OBD tester and mis-firing in cylinder 1 from a faulty spark plug or just a faulty spark plug to add. When asked about the shaking, I mentioned that maybe the timing was off or jumped a tooth and he said probably not because it only shakes in over drive. But when car was started I did happen to see the muffler in the back shaking and I dont remember if it was like that prior. Prior to car getting timing belt replaced it idled rough, stalled after start a few times, shifted into gears late, and had a mild noise coming from what we thought was the timing chain. First thongs replaced were the Crankshaft and Camshaft Senors and the muffler. I think the majority of the exhaust under the car was replaced I'm not too sure it costed me almost $400. After that P0012 code was still on saying timing was retarded. So just this last time, the VVT Solenoid or valve cover was replaced, water pump, and timing chain. After chain was done the P0012 code was off and fhe 02 sensor code was on so he replaced that. As soon as I left the parking lot of the shop the engine light came on and the car was shaky. Now code for 02 sensor and misfiring cylinder 1 and bad spark plug..... ANY IDEAS!!??
 

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given that mileage and it's only misfiring in cyl #1.. it's possible that the spark plug is worn/foul and/or the cop (Coil Over Plug) is worn. Have him test that out. Can just have him swap out the BANK 1 spark plugs/cop with BANK 2. See if the misfiring follows the suspected bad coil/plug. Or if he has the capability, he can also test it all out electronically w/an analyzing oscilloscope. If those are good.. it's fuel/air related.

BUT.. if it were me and fund is available I'd get new COP & Plugs for the BANK 1 since cylinder #1 is in the rear (firewall side) and is a pain to get to (You have to remove the Intake Manifold (being careful not to damage the IM seals), TB, and other various vac hoses, etc). SAVE the old COP & plugs as spare. Mark the mileage, date and which is bad

for the exhaust, it's normal for the exhaust tips to wiggle a bit. The exhaust system hangs on rubber/urethane mounts. They flex and sway a little. If the flex pipe was replace it could be a little rigid since it is still new. It's possible that it may make the whole system behind it move more than the old flex pipe. You do not want a rigid exhaust system because the engine vibration and road bumps will eventually fracture a whole bunch of things
 

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Thank you all for your input it helps me greatly.
Car Details: 2006 Mazda 6 V6 3.0L with 179,000 miles

Called mechanic and asked what was going on now with the O2 sensor and the shaking, and he said the codes for the O2 sensor popped on the OBD tester and mis-firing in cylinder 1 from a faulty spark plug or just a faulty spark plug to add. When asked about the shaking, I mentioned that maybe the timing was off or jumped a tooth and he said probably not because it only shakes in over drive. But when car was started I did happen to see the muffler in the back shaking and I dont remember if it was like that prior. Prior to car getting timing belt replaced it idled rough, stalled after start a few times, shifted into gears late, and had a mild noise coming from what we thought was the timing chain. First thongs replaced were the Crankshaft and Camshaft Senors and the muffler. I think the majority of the exhaust under the car was replaced I'm not too sure it costed me almost $400. After that P0012 code was still on saying timing was retarded. So just this last time, the VVT Solenoid or valve cover was replaced, water pump, and timing chain. After chain was done the P0012 code was off and fhe 02 sensor code was on so he replaced that. As soon as I left the parking lot of the shop the engine light came on and the car was shaky. Now code for 02 sensor and misfiring cylinder 1 and bad spark plug..... ANY IDEAS!!??
Great info. If you have never replaced your spark plugs and coils I would REPLACE THEM ALL now.
I did not know this was a Mk.1 v6 and those are notorious for failing ignition coils (COP) on the rear bank especially (cyl 1,2,3)
What @Oppa said is accurate.

The misfire will cause un-burnt fuel to enter the catalyst and overheat it which results in failed catalytic converters.
I know this personally

I would suggest swapping the bad #1 plug and coil with number 4,5, or 6 and see if the mis-fire follows, but, having been on this forum for years I feel pretty confident (especially if they have never been replaced) they are bad. Labor is money and since you are paying someone to do this just do them once.

I recommend they be replaced every 80,000mi

The only difference I have from oppa is replacing them all. I believe his reasoning is the front are easily accessible and can be done with minimal effort if they turn out to be bad, however.... the computer in these cars does not seem to report mis-fires well and can indeed be having a situation for weeks or months without reporting anything with an engine light.

If you are going to keep the vehicle I would do them all.
DENSO 673 6005 - Ignition Coils x6
Mazda AJTT-18-110 - Spark Plugs x6 (these will be Motorcraft AGSF 22FSCM)
 

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Yes, replacing all of the ignition coils and spark plugs at that mileage is the wise thing to do even if it were running "okay". Just good practice to keep engine healthy.

I suggested only replacing the Bank 1 coils & plugs for troubleshooting measure and future service since you have access to it already. The fronts are easy to do and can be done at a later time if it is still in good working order once all quirks are settled. Expenses can add up.

PCV & PCV hose replacement is also good idea when in there :D
 

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Discussion Starter #8
So I'm having a bunch of wngine codes now for misfires and fuel too lean the codes are P0302, P2187, P2096, P0140, and P2177 and my car still shakes only in overdrive though so I'm completely lost MIND YOU NONE OF THIS STUFF WAS GOING ON BEFORE THE TIMING CHAIN REPLACEMENT, so I'm sure they are related some how and my mechanic said he is "dumbfounded" and doesnt know what's going on...... PLEASE DOES ANYONE HAVE ANY CLUE. I SURE COULD USE SOME USEFUL HELP HERE THANK YOU SO MUCH.
 

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Sorry to hear you are still having troubles. The P0012 was likely the OCV. Timing chains rarely have issue but it is not unheard of.
With the exception of the P0140 code (rear oxygen sensor)ans P0302 (cylinder 2 misfire) the rest are lean codes.
I am curious if your mechanic did a compression check before starting anything. I am wondering if those codes can be accounted for but a vacuum leak. Perhaps when the motor was resembled, some of the intake hoses were left off or incorrectly routed. The intake accordion hose is always a good place to start.
I do not have the 2006 service manual but the P2187, P2096, and P2177 all pertain to lean fuel conditions.
If not a vacuum leak I would look at faulty injector or perhaps injector electrical connector.

Others may chime in with ideas as well.
 
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