Hi,

I have a 4 cyl 2.2L 1995 camry that has developed a problem. It idles very rough with rpms @ 400-500 and has very poor acceleration - no power. I've read the error codes and get 25, 26, and 71. Today was the last day that I'm going to drive it too work. It hasn't stalled on me yet, but when I got home a smelled a little burning and found that exhaust pipe from the manifold to a little past the cat converter almost red hot. I've read that the error codes indicates a possible problem with the EGR system (oxyg sensor, valve, etc.). But, others have had problems with ignition coils with these symptoms. I'm leaning towards investigating the EGR system because one of the main purposes of the EGR systems is to lower the combustion temperature. Since the exhaust pipes were so hot, I figure it must be related to the EGR system. I just can't understand how the EGR system can cause such sluggish performance. Any information that you can provide would be helpful. Thanks.

It is not likely to be the EGR system.

According to the FSM, it could be any one or more of the following:

• Open or short in main oxygen sensor circuit
• Main oxygen sensor
• Ignition system
• Open or short in injector circuit
• Fuel line pressure (injector leak, blockage)
• Mechanical system malfunction (skipping teeth of timing belt)
• Compression pressure (foreign object caught in valve)
• Air leakage
• ECM

Troubleshooting procedure for these codes can be found on pages EG1-363 to 368 of the '94 Camry FSM. Download it from the link in the sticky thread at the top of this forum.

Was there any maintenance performed just prior to this problem popping up?

FYI - Not saying this has got to be the cause but I had codes 25 & 26 on my daughters 94 2.4 ltr last year. Turned out to be a plug wire shorting inside the spark plug tube. Just one of many possibilities.

By any chance is your check engine light flashing? It means something is malfunctioning to the point the cat converter can be damaged.

Connected a hand-vac to the EGR valve and it held no vacuum at all. I believe this means that the EGR valve is bad. Can anybody confirm this? THanks.

EGR is vacuum actuated through the VSV for EGR. Should hold a vacuum. Good find.

I replaced the vacuum modulator valve. Not much impact. I then replaced the EGR valve. The old valve was in bad shape. The opening to the intake manifold was almost entirely block with carbon buildup. Started the car and it sounded alot better. It idled a little high in RPMs, but no engine shaking or low RPMS. But as soon as I put it in gear, the same problem appeared...low RPMS and poor power. I'm thinking that the VSV must be bad as well. I've read that the VSV kicks in when a load is placed on the engine...and since the VSV is electrically controlled it can know when the car is put in gear. Any thoughts?

Also, I checked the ignition coil resistance. All within spec.

Did you go through the list I provided in my previous post? There are some potential problems you can test.

Download the '94 manual from the link in the sticky post at the top of this forum. You can find out how to test the VSV for EGR threre. It is possibly bad.

All else being equal, I'd bet my money on the HO2 sensor or the ignition coil, good resistance in the coil or not. You are not testing the coil's properties with the kilovolt potential under which it operates. Check your spark. It should be bright hot blue with a snap. Anything weaker than that is bad ignition, probably coil. If it does it when the engine is hot or cold, then it is probably not the HO2 sensor.

I replaced the EGR valve. The idle problem went away. But, the car still lacked power. After going through the list, I decided to replace the VSV. Afterwards, I took the car for a test drive and everything seemed fixed. The power was back. Parked the car in front and later decided to take it for a longer test drive. As soon as I took off, the lack of power problem was back. I'm stumped. At this point, I'm wondering whether there is a blockage somewhere. A mouse crawled in my tailpipe or something.

Finally decided to take my car to the shop. Turned out it was a bad couple of spark plugs. The mechanic said that only two cylinders were firing. They replaced the spark plugs, wires, distributer, and rotor.

Apparently the Camry's don't like off the shelf (Bosch) plugs and wires. Tha'ts what my mechanic said. Anyways, I hope all this information is useful to someone.

Yup. Sounds familiar. Thanks for coming back with the fix. The range of possibilities for a fix for a code 25, 26 can appear daunting. Your experience will help many get through that.