Top critical review
too many mistakes, typo and otherwise
Reviewed in the United States on December 20, 2019
The book loses the trust of the reader very early by making some outlandish statements that border intentional mis-information to screw up the reader and it can do that if the readers are not experienced mechanic themselves. I just took my A8 recertification exam for the 4th time and passed again but not by reading stuff like this from this book:
On page 29 author is talking about fuel pressure checking, section 4 3rd line: " It is possible to have correct pressure with little or no volume"!! So next time your fuel pressure gauge shows 48psi, suspect defective fuel pressure gauge.
page47 question13: "technician A says a vacuum leak can occur under the intake manifold and cause oil consumption" and the correct answer is Technician A!! in explanation of the correct answer, author states: " complaint from the customers about excessive oil consumption can be caused by a leaking intake manifold gasket". It might've happened once in the past 100 years.
Author believes the purpose of the secondary air injection is to help the oxygen sensor and the catalytic converter to warm up faster. elsewhere he says the purpose is to help the CAT to oxidize co and hc during the cold start. I've heard this nonsense from other automotive instructors too, started circulating some 15 years ago. Secondary air oxidizes CO and HC in the exhaust manifold independent of the O2 and the CAT. Later on they decided to direct the air to the CAT after closed loop on some older model cars which they don't do that anymore when a car has AIR and CAT. This is why on older cars and trucks, AIR and EGR were used when they were not equipped with O2 or CAT. Even assuming what they say is true, do O2 sensor and CAT warm up faster when exposed to hot manifold exhaust only or when exposed to hot exhaust mixed with cold air from the AIR.
On page 151 question 24, "technician A says EVAP system assists in the reduction of NOX". which is true, vapor reduces NOX by enriching the mixture but the author says NO, "only EGR is in charge of reducing the NOX"
Author also does not know what a lazy O2 sensor does. On page 68 question 19 he shows a snap shot of a scope with o2 sensor waves. All waves are between 300 to 700 mv except one signal that goes over 700mv and drops to almost 200mv. Author says this is a good working O2 sensor when we know this vehicle fails NOX by about 400ppm unless the O2 sensor is replaced. I've fixed many cars in this situation. O2 sensor must go over 800mv and below 200mv repeatedly to be considered good not just once in a while.
Making a long story short, the book was returned as defective.