Skip the auto shop - Our mechanics make house calls

Q: Rich run, bad start, sometimes white smoke

asked by on

Hi, i have deleted DPF and EGR (EGR blank plated and disabled by ecu) after all this problems came. engine rebuild for excessive oil consumption. Car starts bad, sometime smokes white not huge. small black smoke every acceleration. transmission jerking during up and down shift from 1-2-3 and 3-2-1. what can be the reason of problem.

when the car diaqnosed by star diagnostic tool it showed that everything is ok but MASS Air Flow sensor is calculating less air. no error code.

My car has 150000 miles.
My car has an automatic transmission.

The white smoke is a bit worrisome - usually an indicator of a blown headgasket, which will also cause rough running, especially at low speeds from a compression imbalance. The throttle position sensor may also be sending "off" signals to engine management, resulting in a bit of a rich mix, and harsher shifting.

To avoid any unnecessary repairs, I would recommend having a certified technician, like one from YourMechanic, diagnose your shaking/vibrating condition to confirm there is a problem, get an accurate assessment of damage and cost estimate for repairs. YourMechanic can dispatch a mobile, professional mechanic to your location for this repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Rich run, bad start, sometimes white smoke

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

Get a quote

What others are asking

Q: Starter issues with my car in cold weather.

Hello, Being that the noise only happens below freezing, you should record it for a second opinion. If you believe that the starter is staying engaged, then you might need a starter motor. Note that with extremely cold temperatures cars...

Q: Does my 2001 Mercedes need Motor mounts? How many motor mounts are there?

Your car has two motor mounts in the front and one transmission mount at the rear. The Front motor mounts soak up most of the engine vibration and last for about 10 or 12 years before they start to get...

Q: Hood release not working

It sounds like the cable for the hood release has broken. These cables usually break at the connector under the dash. If this is the case, you can still open the hood; just find where the cable connects, and pull...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.