Linked Questions

11
votes
5answers
6k views

How critical is it to match the stock fuel pressure regulator pressure when replacing it?

My fuel pressure regulator needs replacing, however the original part from the manufacturer is outrageously expensive. While looking for less financially painful alternatives I've seen much cheaper ...
6
votes
3answers
12k views

Diagnosing P0171 2007 Toyota Corolla

First time poster trying to get into cars. So my 2007 Toyota Corolla (with around 89k miles) has a Check engine light that reads error code P0171 (System too lean Bank 1). I was looking that up and ...
11
votes
1answer
2k views

How do lambda sensors work?

Virtually every modern passenger vehicle today utilizes lambda sensors from the factory. How critical are they to a vehicle's operation? How do they work?
4
votes
1answer
7k views

Engine misfires when car hasn't been driven for a couple of days

My 2001 Hyundai Elantra XD suffers from misfires during the first 5-10 minutes after starting the car. After this, the car runs as as it should. I'm not sure, but I think the misfires only happen when ...
10
votes
1answer
2k views

A most intriguing cold-start misfire mystery

I'm trying to help a friend out with a CEL on his 2009 Merc GLK 280. Hooked it up to an OBD2 reader and retrieved a single code: P0300 - 'Random/Multiple Cylinder Misfire Detected', via the 'OBD ...
6
votes
2answers
1k views

Is a bad AFM (Air Flow Meter) a likely cause for fuel cut at high RPM and poor performance at low RPM?

Edit: I answered my own problem, the solution was the AFM (see full answer below). This question is for the same engine and the same car as in the following question: Likely cause of poor performance ...
4
votes
2answers
1k views

Mazda3 2013 Skyactiv-G 2.0, after 3 years using 5w40 is it Ok to lower the grade (thinner oil like 5w20 or 0w20) as recommended by manufacturer?

Context Mazda 3, US version, model 2013, Skyactiv 2.0 engine, gasoline, hatchback, manual transmission. I got the car from the US with 24,000 miles and 0w20 Penzoil full synthetic on it, according ...
5
votes
1answer
1k views

What does the ECU use the long term fuel trim for?

I have a 2001 Honda Prelude SH (Honda H22A4 engine). I was trying to determine how the reported short/long term fuel trims fit in to the fuel control loop (in particular I was wondering if the long ...
6
votes
1answer
257 views

What exactly is R-1234yf?

I keep on reading about a new refrigerant, R-1234yf, that is being adopted by some automotive manufacturers. What is this refrigerant all about, why are manufacturers considering it and what makes it ...
1
vote
0answers
491 views

fuel consumption in CR-V 2007

lately I found my car consuming more fuel than usual,it was doing 8 liters per 100km,then it raised to 12 liters per 100km,I asked its agency to check for the problem,they found nothing unusual,after ...