G4125 Gastester Digital

I suspected I had a rich mixture so I bought this. I followed the instructions and I adjusted my mixture until I reached the target CO spec (for an older Porsche 928) and now the car runs better than it ever has before. I recommend.

The unit is a bit cheaply made (plastic), and not robust at all. However, it seems to work OK. Has sufficient length power cable and the plastic exhaust tubing is long enough. So far the plastic tubing hasn't melted. The CO readings seemed to fall in line with what the NJ state inspection station reading for CO was. I have only used it twice, and will revisit to adjust my rating at some point down the line.

Works well for tuning vintage autos, but read and understand the directions! Proper calibration is key - this isn't a toy, you have to think about how you are using it.

Requires a lot of warmup time, about 30 minutes, to get accurate readings. It's also a bit flimsy. Not bad for the price paid.

It takes a while to learn to use it, but once you do it works quite well.

Worked as stated. No issues

I'm very pleased with this exhaust gas analyser. I totally recommend this product. Everything was good with the seller, I recommend him as well.

This gas exhaust gas analizer works pretty good, the only reason is that does not get 5 stars is that is not very accurate, the advertised accuracy is 0.5% for CO which helps but it is on the border on being useful since California DMV has some very strict requirements, and under those requirements 0.5% of error is a lot.However this is a must tools for older cars to pass emissions, it does not measure other gases that are required by dmv, however by having a low CO you will most likely have low hydrocarbon emissions too.This tester will not guarantee that you pass emissions on DMV especially in California, but it will greatly increase your chances of success, a tester that would guarantee success on DMV would cost over 10x the price.The proper way of using this tool which is not documented anywhere, is to remove that CAT, then check the exhaust and do the proper adjustments, and then put the CAT back before going to DMV this will most likely assure you pass emissions.The reason the CAT needs to be removed, is to get as much of an accurate reading as possible, since the CAT will capture much of the CO, the reading would not be accurate with a CAT, however even with the CAT on it will help however your reading will not be accurate, but it will help in the sense that if the reading are high for CO with the CAT installed, you will fail emissions for sure.Also most smog places are under a lot of regulations for the governments, the only smogs check that they will do are for official smog checks, and that is something you want to do only after an smog check tunning, and that is precisely what make this tool very valuable, most smog check places will not do any smog check tunning even if you pay them to tune your car, they will only follow the official procedure, and the official procedure seems that you have to fail first before any tunning is done to the car.I used it on a van e150 and it works fine with gasoline and also on propane, the plastic tube will melt over time it does not resist the exhaust temperature very well.tips for passing emissions:1. check the co with this tool and make it as low as possible without the engine failing, the recommended % of CO by mechanics for older cars is too high to pass emissions, at the required level by DMV an older car will run very lean, but that leanness in fuel fixture is required today to pass emissions. if you tune for best performance it will fail emissions.2. ethanol in fuel is very bad for your engine, however it is good for emissions, so before going to a dmv check, it is good to use ahead of time fuel with ethanol for the leaner emissions. Ethanol has very low lubricity and will damage an engine, but helps lowering emissions, that is why many fuels come with ethanol in it.3. use a clean air filter with low air resistance such as k&n.4. have clean oil in your engine, since some oil flows to the air filter where it is used for combustion, for older engines oil with more viscosity is better.