Nissan Maxima QX

1. The diagnostic equipment for check of serviceability of a condition of the catalytic converter is expensive and extremely difficult in operation. At emergence of suspicions on failure of the converter, drive away the car for check on car repair shop.
2. Every time when the car climbs any reason above the ground, examine the converter on existence of signs of mechanical damages, traces of leaks and development of corrosion. Check a condition of welded seams and reliability of tightening of flange bolts of fastening of the device to sections of system of production of the fulfilled gases. The defective catalytic converter is subject to replacement.
3. Despite reliability of a design of the converter, there is rather high probability of its obstruction. The simplest way of check of passability of the converter is check with use of the vacuum gage:

a) Connect the vacuum gage to a source of depression of the inlet pipeline (see the Part the General capital repairs of the engine of the Head Dvigatel);
b) Warm up the engine up to the normal working temperature, transfer the selector lever to situation "P" (models from AT), or include neutral transfer (models with RKPP) and cock the parking brake;
c) Consider indications of the vacuum gage at single turns of the engine;
d) Open a butterfly valve, having lifted the frequency of rotation of the engine to 2000 rpm;
e) Quickly release the gate and consider indications of the vacuum gage;
f) Repeat the described check still three times, every time writing down result;
g) If the result of the fourth measurement appears more than on 2.5 mm of mercury. below the instrument read at single turns, therefore, there is a probability of violation of passability of the converter, or an exhaust pipe.

See the Head of the Power supply system and release (The section devoted to service of system of production of the fulfilled gases).