Catalytic Converter

Palmer's Auto Repair - Catalytic Converter | imagePalmer's Auto Repair can diagnose catalytic converter problems and replace catalytic converters. Just a few of the problems you can experience are: one of the catalyst plates gets loose and rattles; the converter gets clogged and causes the car to run rough and get terrible gas mileage; they can leak exhaust;  they can wear out and stop doing their job.

Catalytic converters have no moving parts but they do have a number of features that can cause major problems with your vehicle.   Here's an explanation how a catalytic converter works.

Newer cars control the amount of fuel they burn electronically so that there is very little left over once the fuel and air are burned by the engine. Theoretically, all of the fuel gets burned and all of the oxygen gets burned. Unfortunately, the fuel mixture varies quite a bit during driving and it isn't always perfect so you end up with emissions.

The by-products (emissions) when you run a gasoline engine are Nitrogen gas (N2), Carbon dioxide (CO2), and water (H2O).  These gases are mostly benign and don't require emission control.

Because the combustion process is never perfect, some small amounts of harmful emissions are also produced by car engines: Carbon monoxide (CO), Hydrocarbons (VOCs), and Nitrogen oxides (NO NO2, and NOx). These three gases contribute to smog and acid rain, and are irritants to your eyes, nose, and throat. Catalytic converters are designed to reduce these harmful emissions.  They do this by using catalysts.

A catalytic converter uses two different types of catalysts.  They use a reduction catalyst and an oxidation catalyst. Both types consist of a ceramic structure coated with a metal catalyst,: platinum, rhodium and/or palladium. The unit is designed so that the exhaust flows over the catalyst surface on its way through the exhaust stream.  Most modern cars are equipped with three-way catalytic converters. This refers to the three regulated emission gases that are reduced by the two catalysts.

A reduction catalyst is the first stage of a catalytic converter. It uses platinum and rhodium to reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst breaks the molecule.  The nitrogen atom pops out of the molecule and sticks to the catalyst, freeing the oxygen. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2.

The oxidation catalyst is the second stage of a catalytic converter. It reduces unburned hydrocarbons and carbon monoxide by burning (oxidizing) emissions over a platinum / palladium catalyst. This catalyst aids the reaction of the CO and hydrocarbons using the remaining oxygen in the exhaust. Just so you know, every one of these catalyst materials is more expensive than gold.  That's why a quality replacement converter is expensive.

Palmer's Auto Repair - O2 Sensor | imageLastly, there is an exhaust system monitoring system that senses how much CO, VOC, and NOx there is in the exhaust. These monitors control the fuel/air mixture at the engine intake. In particular, an oxygen sensor is mounted in the exhaust before the catalytic converter. It tells the engine computer how much oxygen is in the exhaust. The monitor will increase or decrease the amount of oxygen in the exhaust by adjusting the air-to-fuel ratio. This allows the engine to run at its highest efficiency and makes sure that the catalytic converter is eliminating the maximum amount of unwanted emissions.


DEQ Specialists

Palmer's Auto Repair Technician - Tony | imagePalmer’s Auto Repair technicians are regularly sent to night training courses to keep up with the constantly evolving smog control technologies from all the different auto and truck manufacturers. Our up-to-date knowledge of DEQ requirements, ‘drivability’ diagnostic skills, and smog control system functions means we have no problems getting a car through DEQ. The term drivability describes the experienced skill of a diagnostic technician when analyzing engine starting process, idling smoothness, engine operation when cold and when hot, shut-down smoothness, operation under acceleration and deceleration, performance under load, indications of miss-firing, back-firing, or dying with our without any pattern.

From carburetors to catalytic converters, we know DEQ standards and regulations we take the worry and time out of getting your car smogged.  With our advanced DEQ equipment we will receive your car, tune it up, and make sure it's up to DEQ requirements.  If you like we’ll take it to DEQ for testing, and return it to you with the new tags on it! Palmer’s Auto Repair understands all makes and models, and all DEQ regulations and standards. Bring your car to Palmer's Auto Repair and be confident that your car will get through DEQ!  Call us today at (503) 654-4343.

Diagnose and Repair Check Engine Lights

Check Engine Light


I think everyone has at one time or another looked down to see that the yellow or red check engine light indicator has come on.  Now what?  Check engine light diagnosis is important to get done as soon as possible.  Sometimes, certain functions of the car won’t work anymore (like your cruise control) because the auto manufacturer really wants you to take care of the problem right away.

At Palmer’s Auto Repair, we believe in accurate diagnosis to prevent you as the customer from paying for unnecessary repairs.  If your check engine light is on, drop by the shop for a *free* code-scan.  We can advise you whether or not your vehicle needs a repair or if there’ a simple fix for your problem.

Emission Systems Repairs / DEQ

Palmer's Auto Repair - Smog Check SymbolAuto manufacturers have gone to great lengths to develop vehicles that get good gas mileage while reducing the amount of pollutants that reach the air.  In order to accomplish this, the emission systems for all vehicles have become a complex coordination between catalysts, gas sensors, fuel delivery control, and electronic brains that manage and coordinate these systems.  When any one of these gets out of sync, the engine may run poorly, get low gas mileage, and will not pass a DEQ test.

Is your check engine light preventing your vehicle from passing the DEQ test.  Having trouble getting your registration?  Did your car fial DEQ for smoke, or dirty exhause fumes?

At Plamer's we are here to help!  Our wide range of test equipment allows us to see exactly what DEQ sees.  We can advise you on repairs to get you through DEQ and back on the road.

Palmer’s Auto Repair has a history of quickly diagnosing emission system problems. Usually a drivability test will reveal the general section of the system that is the problem. Then an emission system electronic diagnosis will pin point it.  We will be able to tell you exactly what the problem is and what it will take to fix it.  From EVAP control, to exhaust gas sensors, catalytic converters, and fuel delivery, Palmers will provide a reliable emission system diagnosis quickly, usually less than 30 minutes and always less than an hour.  Call us at (503) 654-4343.

Exhaust and Mufflers

Most exhaust system failures don't require an exhaust shop to fix them. Palmer’s Auto Repair is a complete exhaust pipe repair shop.  We have a lot of experience with all makes and models of cars, trucks, diesels, and we have a lot of experience  installing high performance exhaust systems.  It’s important to note that your car’s fuel delivery system is integrated into your exhaust system.  That means that if you have an exhaust leak then your engine my not be getting the right air/fuel mixture.  That can cause very poor performance and, over time, may even damage your engine.  It’s important to get exhaust leaks fixed as soon as you can.

Palmer’s Auto Repair also specializes in high performance exhaust systems.  In Oregon, we are really fortunate.  The Oregon law requires that your exhaust system not exceed the decibel limit for your vehicle.  Also, exhaust system modification is legal as long as the car still meets its emission control standards.  While you can’t remove the catalytic converter there are such things as a low back pressure cats that help to improve performance and still protects our environment.

One of our customers had a Subaru WRX.  We changed out the whole exhaust system, putting in new pipe from the turbo to the tail with a low flow cat.  Along with a tune up, the car not only passed the smog tests by a mile but the gas mileage improved from 24 mpg on the freeway to 35 mpg!

You’d be surprised what an exhaust system repair will do for your car’s performance.  Call us at (503) 654-4343 and let’s talk about your car’s needs.

Fuel Injector Cleaning

Palmers Auto Repair Fuel Injector DiagramOften times the fuel injectors, intake valves, and the throttle body are forgotten.  The manufacturers start recommending injector cleaning after 60,000 miles and sometimes there are “Technical Service Bulletins” for you vehicle recommending that your injection system is cleaning to fix rough idle, inspect or replace for expansion cracking, lean fuel conditions, and check engine lights.  When you come in for service we check the entire vehicle for needs.  We also look over the maintenance history with you, even if it’s a stack of receipts from other shops, and alert you of upcoming maintenance intervals.

Here at Palmer’s we are big on preventative maintenance.  We feel it’s better to keep injectors, intake valves, and throttle bodies clean and performing at maximum efficiency rather than wasting money on precious gas because slowly degenerating injector conditions are causing a loss in gas mileage.  Dirty throttle bodies are the leading cause of engine dying while idling at a stop.  That’s why we consider a throttle body cleaning part of normal maintenance.  Palmer’s fuel injection maintenance also cleans the carbon build up off of the intake valves.  That will increase fuel economy and reduces the chance of ‘pinging’.

In the old days we used to slowly pour water down the carburetor while the engine was running to clean carbon out of the engine.  Please don’t try this now.  There are too many ways to damage a modern engine doing this.

Experience has shown that getting good gas mileage and getting regular maintenance for your car will put a smile on just about anyone’s face.  Come see us at Palmer’s Auto Repair.  It’s great to give a smile and get one back, and this way is the one we enjoy the most.