I have been experiencing an intermittent issue with engine performance - engine will all of a sudden start misfiring and lose power with inability to run past 25 - 30 mph. If accelerator is pressed in attempt to increase speed, engine vibrates violently. When the engine is turned off and restarted, it runs normally for a period of time of a minimum of a few days - weeks. Dealership performed computer diagnosis and unable to identify any related codes or mechanical problems. They told me to just continue to drive until problem recurs and then bring it back during normal hours without turning off so they could attempt to pull a code without allowing computer to reset. Have been unable to reproduce during normal hours. Told by one dealership technician that it sounds like master air flow sensor. I never receive a check engine light or other warnings prior to, during, or after the occurrence. Please help!!!!! Thanks!

 

how many miles do you have? ever clean out your throttle bodies?

 

I'd have to agree with the dealership that this sounds like a sensor malfunction, specifically, the MAF.

Mass Airflow Sensor: An Easy Fix for Big Problems from a Little Instrument

I'm not sure what the error condition is that throws an ECU code (voltage?), but it could be that the sensor is malfunctioning within the confines of normal operation and a code is never thrown. I would try to get a second opinion as this sounds like classic sensor failure.

I've never replaced one of these myself and have owned cars with over 100K miles. After market oiled air filters have been linked to failure, and I have heard of people cleaning them with mixed results. Personally, I think I'd replace.

Good thread here on the subject: BAD MASS AIR FLOW SENSOR - Nissan Forum | Nissan Forums

 

I have 103K and have not cleaned out the throttle bodies. Planned to systematically isolate problem - start with cleaning MAF Sensors, replacing air filters, etc. Just strange that there's no warning and after turning engine off, it starts up right away and generally runs fine for days/weeks! What else could it be?

 

Thanks sockets67! Took car to Nissan and Infiniti since I've had good relationship with both. Infiniti tech said to systematically check those associated things myself rather than letting them charge me labor hours chasing a ghost without an error code. So, you're saying to stay away from oiled filters (K&N, etc.)?

 

As I am attempting to isolate the performance issue I am having, can anyone give me their recommendation for engine air filters? Thanks!

 

Anything other than k&n drop in filters

 

Any OEM equivalent filter is probably as good as the next. I personally use Wix.

 

AFE Dry drop in filters

 

NAPA Gold filters are made by WIX. That's what I use, but the dealer always warns me that "paper" filters are not recommended. They claim the factory filters are oiled. The NAPA gold filters are a fraction of the cost, and I change them every 10K miles.

 

Mine had bad start up issues... cleaned the mafs and bam! car has better fuel economy and even it feels like it "clutches" better when accelerating when shes fully stopped... (6mt though). obviously the start up issues are gone too.

 

EverReady959 - maybe you want to start with trying to clean the MAF? Follow the instructions carefully as these sensors are pretty fragile. It worked for Claudiohv, so this may be a low cost solution to your issue.