Gear change issue, help! Nissan Note 1.5 D 2012

Flatulentoldgoat

For some reason, I've always found some initial sluggishness when I change up from 3rd - 4th gear. It's almost like turbo lag and I've always sort of lived with it. Well, today I hooked up an OBD reader and it did return one interesting code and I wonder if there's a link?  P0170 NISSAN - Fuel Trim Malfunction Bank
Just for good measure I have wiped the code and I'll see if it returns. Based on turning the car on and off again it hasn't cropped up again and I may need an extended test drive before the juries out.
Any thoughts? 

AdrianC

Fuel trim is the range in which the engine management can adjust the fuelling up or down, to richen or lean the mixture, according to the exhaust gases. It's different, obvs, on a diesel to a petrol, because there's no throttle and engine revs are varied by increasing or decreasing fuelling, rather than increasing or decreasing air.

But the fault code is saying that the acceptable range of trim has been exceeded - it's got to the end of the adjustment it's got... So, no, it may not come back immediately - but it may well do at some point in the future. On a petrol, it could be as simple as an air leak. On a diesel... worn injectors? Simplest... when was the air filter last changed?

("Bank" will be Bank 1 - it's a straight engine, so there is only one bank. If it was a V, then it'd be Bank 1 (one side of the V) or Bank 2 (the other).)

Flatulentoldgoat

I really hope it's not the injectors going out, I'm only at 80k. I do know that there is a slight split in one of the air intake hoses. The hose consists of two plastic halves that snap together if that makes any sense and it's a little bit loose. That's probably the best bet. Also, I recently pulled out the air filter and found some crud in it which I removed. About to replace the air filter so we shall see. The process of elimination begins but please please don't say injectors :-(

AdrianC

It's just one suggestion.

There'll be an air flow sensor or meter in there, measuring the air entering the engine. I presume that leak is before that? If not, that could well be your cause.