Defective ignition coil(s) Bad spark plug(s), spark plug wires, or spark plug boots. Faulty fuel injector(s) Malfunctioning fuel delivery system (fuel pump, fuel pump relay, fuel injectors, or fuel filter) Major engine vacuum leak. EGR valve stuck in the wide open position. Clogged EGR ports.
The following conditions can sometimes cause smelly urine, but they are uncommon: 1  urinary stones â these may cause an ammonia-like odour (read about bladder stones and kidney stones) 2  a bladder fistula â this is an abnormal connection between your intestines and bladder.
4 doctors agreed: Asparagus, garlic...: The most well known food to cause urine to have an odor is asparagus, which leads to excretion of dimethyl sulphide, methyl mercaptan, & asparagusic acid that cause the characteristic odor. Garlic can impart odor to the urine, and alter the results of urinalysis tests.