Q: Rich run, bad start, sometimes white smoke

asked by on October 13, 2016

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.

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

What others are asking

evaporative emission system leak

It sounds like you may have an evaporative emissions system leak. Your car has a small purge valve with a purge solenoid in the Evaporative Emissions system that controls the venting of fumes from the fuel tank as these fumes...

Last night I was driving home and I heard this knocking noise, a minute later the noise went away and my check engine light came on.

Hi there. The noise you heard could have been the engine knocking due to a lack of engine oil. If the brake pedal is pressed and the oil light comes on, then the oil level could be low causing the...

Cars shakes, like driving over invisible potholes

The vibration in the steering wheel is due to dynamic imbalance, excess radial force variation in the tires and/or faults (looseness) in the suspension that permits the residual imbalances that are normally held in check by a tight suspension to...

Engine sputtering after refueling

Hi There, This is likely related to your EVAP emissions system and something called a purge solenoid. The EVAP system prevents fuel vapors from the fuel tank from escaping into the atmosphere. The EVAP system collects and temporarily stores the...

Brake lights work intermittently

If you had the dealer fix something and paid for the repairs, then I would take it back to them to have them fix it right. The lights coming on may be problems with a loose electrical connection, or a...

My car bogs down abit after a cold start and then accelerates fine after that

There are a number of things that may cause the car to hesitate when accelerating when cold such as low fuel pressure, a dirty or faulty mass air flow sensor, clogged or dirty fuel injectors, or potentially a bad oxygen...

High idling 3000-4000 rpm after cleaning throttle body...even after warming .....relearn procedure not working nissan altima 2007

Hi Muhibur. Thanks for sending your question today. This could be either a vacuum leak or an issue with the ECU that is causing this high RPM issue. The only way to know for sure is to have a professional...

Code P0340

Hi There, Your vehicle should have two camshaft position sensors. If only one of them was replaced, it may not have been the faulty one. Secondly, you may also want to have the wiring and connections to the camshaft sensors...

Sunroof stuck open

Hi there. A jammed sunroof is caused usually because of gathered dirt along the track obstructing the sliding of the sunroof. Another possible issue can be that your sunroof motor has weakened over usage. You can have a certified mechanic,...

Related articles

Can You Switch Between Regular and Synthetic Motor Oil?
If you have ever wondered if you can switch between regular and synthetic motor oil, you need to consider what type of oil works best for your engine.
How to Buy a Good Quality Oil Pan Gasket
When When your garage floor looks like an oil slick, there’s a good possibility that you will be shopping for a new oil pan gasket in the near future. While oil leaks can also be caused by a loose oil...
Symptoms of a Bad or Failing Oil Return Hose
Common signs include cracks or bulges on the hose and noticeable oil leaks.