Q: Does seafoam cause problems to your car such as choking before start and temperature gauge to lower when accelerating

SeaFoam is implicated in anecdotal reports (i.e., unverified, episodic; non-controlled circumstances) of engine/component damage. Like virtually all OEM vehicle manufacturers, Toyota does NOT recommend Sea Foam, or ANY other aftermarket treatments or "additives" like it for use in fuel or oil or direct introduction to the air intake. There are very limited exceptions to this rule, for example GM fuel system cleaners. Gas stabilizers might be another example if the vehicle is to be stored for more than a month. These aftermarket "additives", usually sold with exaggerated claims, and with no published or publicly available scientific evidence, or independent third party laboratory testing, are generally a waste of money, usually are priced irrationally (i.e., the cost of the product has no rational or reasonable relationship to the actual economics of producing the product) and, most important of all, are not recognized or approved by vehicle and part manufacturers as a legitimate, useful or proven material for use in vehicle maintenance and repair. In your particular circumstance, the fluctuation in the temperature gauge may reflect a sensor, gauge or electrical defect. Engine temperature does fluctuate based on operating conditions but you will not see an immediate response on a temperature gauge merely by pushing on the accelerator unless there is some defect (perhaps even including a problem with the thermostat). If you desire that the issue with the temperature gauge be diagnosed, please refer to YourMechanic’s electrical component diagnostic service request page. If the hard starting (choking in your circumstance) you are referring to occurred immediately after using SeaFoam in the intake it is possible that debris has fouled the spark plugs and/or has even deposited on the valve seats. That is speculative, of course, but a point is these aftermarket materials are neither recommended, nor even needed, and if trouble began immediately after using the material, yes, it is possible there is a link. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.